Chapter 3 Preview

Silber4 3.003.AP. ,

Why might the expression "1 mole of nitrogen" be confusing?

Key: "1 mole of nitrogen" could be interpreted as a mole of nitrogen atoms or a mole of nitrogen molecules.

What change would remove any uncertainty?

Key: Specify a mole of nitrogen atoms or a mole of nitrogen molecules to avoid confusion.

For what other elements might a similar confusion exist? (Select all that apply.)

[_] lithium

[x] chlorine

[x] sulfur

[_] argon

[_] aluminum

[_] neon

[x] bromine

[x] phosphorus

Why?

Key: The same problem is possible with other diatomic or polyatomic molecules, e.g., Cl₂, Br₂, S₈, P₄.

Silber4 3.004.EOCP.

Which is true for molecular mass and/or molar mass?

(_) Both represent the SI unit for the amount of a substance.

(o) Both will have the same numeric value for a given chemical substance.

(_) Molar mass will have units in amu.

(_) Molecular mass will have units in g/mol.

Silber4 3.005.EOCP.

Which is not true about the mole?

(_) It maintains the same mass relationship between macroscopic samples as exist between individual chemical entities.

(o) It represents a mass unit.

(_) It relates the number of chemical entities to the mass.

(_) It is the amount of a substance that contains the same number of entities as there are atoms in exactly 12 g of carbon-12.

Silber4 3.007a.EOCP.

Each of the balances below weighs the indicated numbers of atoms of two elements.

On Scale (a) which element has the higher molar mass?

(_) the element on the right

(o) the element on the left

(_) neither element

(_) not enough information to decide

Silber4 3.007b.EOCP.

Each of the balances below weighs the indicated numbers of atoms of two elements.

On Scale (b) which element has more atoms per gram?

(_) the element on the right

(o) the element on the left

(_) neither element

(_) not enough information to decide

Silber4 3.007c.EOCP.

Each of the balances below weighs the indicated numbers of atoms of two elements.

On Scale (c) which element has fewer atoms per gram?

(_) the element on the right

(o) the element on the left

(_) neither element

(_) not enough information to decide

Silber4 3.007d.EOCP.

Each of the balances below weighs the indicated numbers of atoms of two elements.

On Scale (d) which element has fewer atoms per gram?

(_) the element on the left

(o) neither element

(_) the element on the right

(_) not enough information to decide

Silber4 3.012.AP.

Calculate each of the following quantities.

(a) mass in grams of 0.67 mol KMnO₄

WebAssign will check your answer for the correct number of significant figures.

[110] g
(b) moles of O atoms in 7.56 g Mg(NO₃)₂

[0.306] mol
(c) number of O atoms in 6.0

10^-3 g CuSO₄ · 5 H₂O

[1.3e+20] atoms

Silber4 3.013.AP.

Calculate each of the following quantities.

(a) mass in kilograms of 3.4

10²⁰ molecules of NO₂

[2.6e-05] kg
(b) moles of Cl atoms in 0.0535 g C₂H₄Cl₂

[0.00108] mol
(c) number of H ^- ions in 5.39 g SrH₂

[7.24e+22] ions

Silber4 3.013a.EOCP.

Calculate the mass in kilograms of 3.8

10²⁰ molecules of NO₂.

(_) 2.90

10^–2 kg NO₂

(_) 1.7

10¹⁹ kg NO₂

(_) 1.75

10²² kg NO₂

(o) 2.9

10^–5 kg NO₂

Silber4 3.013b.EOCP.

Calculate the moles of Cl atoms in 0.0425 g of C₂H₄Cl₂.

(_) 4.2951

10^-4 mol Cl atoms

(_) 2.10 mol Cl atoms

(_) 8.5

10^-2 mol Cl atoms

(o) 8.59

10^-4 mol Cl atoms

Silber4 3.014.AP.

Calculate each of the following quantities.

(a) mass in grams of 0.55 mol MnSO₄

[83] g
(b) moles of compound in 13.4 g Fe(ClO₄)₃

[0.0378] mol
(c) number of N atoms in 80.5 g NH₄NO₂

[1.52e+24] atoms

Silber4 3.014b.EOCP.

Calculate the moles of compound in 15.8 g of Fe(ClO₄)₃.

(_) 5.6

10^-2mol Fe(ClO₄)₃

(o) 4.46

10^-2mol Fe(ClO₄)₃

(_) 1.338

10^-1mol Fe(ClO₄)₃

(_) 3.36

10²²mol Fe(ClO₄)₃

Silber4 3.015.AP.

Calculate each of the following quantities.

(a) total number of ions in 28.7 g CaF₂

[6.64e+23] ions
(b) mass in milligrams of 2.18 mol CuCl₂ · 2 H₂O

[3.72e+05] mg
(c) mass in kilograms of 3.44

10²² formula units of Bi(NO₃)₃ · 5 H₂O

[0.0277] kg

Silber4 3.015b.EOCP.

Calculate the mass in milligrams of 3.58 mol of CuCl₂ · 2 H₂O.

(o) 6.10

10⁵mg CuCl₂ · 2 H₂O

(_) 5.5304

10⁵mg CuCl₂ · 2 H₂O

(_) 5.5

10⁴mg CuCl₂ · 2 H₂O

(_) 6.1

10²mg CuCl₂· 2 H₂O

Silber4 3.015c.EOCP.

Calculate the mass in kilograms of 2.88

10²² formula units of Bi(NO₃)₃ · 5 H₂O.

(o) 2.32

10^-2kg Bi(NO₃)₃ · 5 H₂O

(_) 1.4

10²² kg Bi(NO₃)₃ · 5 H₂O

(_) 1.880

10^-2 kg Bi(NO₃)₃ · 5 H₂ O

(_) 1.12

10²²kg Bi(NO₃)₃ · 5 H₂O

Silber4 3.016b.EOCP.

Calculate the mass in grams of 2.04

10²¹ molecules of dinitrogen pentaoxide.

(o) 0.366 g N₂O₅

(_) 0.64 g (NO₅)₂

(_) 2

10²³g N₂O₅

(_) 3.836

10²³g (NO₅)₂

Silber4 3.016d.EOCP.

Calculate the number of formula units in 57.9 g of sodium perchlorate.

(o) 2.85

10²³formula units NaClO₄

(_) 3.3

10²³formula units NaClO₃

(_) 4

10²³formula units NaClO₂

(_) 4.685

10²³formula units NaClO

Silber4 3.017.AP.

Calculate each of the following quantities.

(a) mass in grams of 2.05 mol chromium(III) sulfate decahydrate

[1170] g
(b) mass in grams of 9.46

10²⁴ molecules of dichlorine heptaoxide

[2870] g
(c) number of moles and formula units in 59.2 g lithium sulfate
moles

[0.539] mol
formula units

[3.24e+23] formula units
(d) number of lithium ions, sulfate ions, S atoms, and O atoms in the mass in part (c)
Li⁺ ions

[6.49e+23] ions
SO₄^2- ions

[3.24e+23] ions
S atoms

[3.24e+23] atoms
O atoms

[1.30e+24] atoms

Silber4 3.017a.EOCP.

Calculate the mass in grams of 3.52 mol of chromium(III) sulfate decahydrate.

(_) 1.5

10³g Cr₂(SO₄)₃ · 10 H₂O

(_) 1.32

10³g Cr₃(SO₄)₂ · 10 H₂O

(_) 1.860

10³g Cr₃(SO₄)₂ · 10 H₂O

(o) 2.02

10³g Cr₂(SO₄)₃ · 10 H₂O

Silber4 3.017b.EOCP.

Calculate the mass in grams of 9.64

10²⁴ molecules of dichlorine heptaoxide.

(_) 2.7

10³g Cl₂O₆

(_) 5.78

10²²g Cl₂O₆

(_) 5

10²²g Cl₂O₇

(o) 2.93

10³g Cl₂O₇

Silber4 3.017d.EOCP.

Calculate the number of formula units in 56.2 g of lithium sulfate.

(_) 4

10²³formula units Li₂SO₃

(_) 3.9

10²³formula units LiSO₃

(_) 3.25

10²³formula units LiSO₄

(o) 3.08

10²³formula units Li₂SO₄

Silber4 3.020b.EOCP.

Calculate the mass fraction of O in uranyl sulfate trihydrate (the formula for the uranyl ion is UO₂²⁺).

(_) 0.2601 mass fraction O

(o) 0.3428 mass fraction O

(_) 0.32 mass fraction O

(_) 0.226 mass fraction O

Silber4 3.021b.EOCP.

Calculate the mass fraction of P in tetraphosphorus hexaoxide.

(_) 0.453 mass fraction P

(_) 0.52 mass fraction P

(_) 0.4918 mass fraction P

(o) 0.5634 mass fraction P

Silber4 3.022.AP. ,

Oxygen is required for metabolic combustion of foods. Calculate the number of atoms in 38.0 g oxygen gas, the amount absorbed from the lungs at rest in about 15 minutes.

[1.43e+24] atoms

Silber4 3.022.EOCP.

Oxygen is required for the metabolic combustion of foods. Calculate the number of atoms in 38.0 g of oxygen gas, the amount absorbed from the lungs at rest in about 15 minutes.

(_) 2.86

10²⁴O atoms

(_) 2.288

10²⁵O atoms

(_) 7.2

10²³O atoms

(o) 1.43

10²⁴O atoms

Silber4 3.023.AP.

Cisplatin (below) is a powerful drug used in the treatment of certain cancers.

(a) Calculate the moles of compound in 275.1 g cisplatin.

[0.9167] mol
(b) Calculate the number of hydrogen atoms in 0.96 mol cisplatin.

[3.5e+24] atoms

Silber4 3.023a.EOCP.

Cisplatin (below), or Platinol, is a powerful drug used in the treatment of certain cancers.

Calculate the moles of compound in 285.3 g of cisplatin.

(_) 0.95 mol Pt(NH₃)₂Cl₂

(_) 0.95068 mol Pt(NH₃)₂Cl₂

(_) 0.951 mol Pt(NH₃)₂Cl₂

(o) 0.9507 mol Pt(NH₃)₂Cl₂

Silber4 3.023b.EOCP.

Cisplatin (below), or Platinol, is a powerful drug used in the treatment of certain cancers.

Calculate the number of hydrogen atoms in 0.98 mol of cisplatin.

(_) 3.54

10²⁴H atoms

(_) 3.541

10²⁴H atoms

(_) 4

10²⁴H atoms

(o) 3.5

10²⁴H atoms

Silber4 3.024.AP.

Allyl sulfide gives garlic its characteristic odor.

(a) Calculate the mass in grams of 1.63 mol allyl sulfide.

[186] g
(b) Calculate the number of carbon atoms in 4.67 g allyl sulfide.

[1.48e+23] atoms

Silber4 3.024a.EOCP.

Allyl sulfide (below) gives garlic its characteristic odor.

Calculate the mass in grams of 1.63 mol of allyl sulfide.

(_) 1.427

10^-2g S(C₃H₅)₂

(_) 1.43

10^-2g S(C₃H₅)₂

(_) 186.2 g S(C₃H₅)₂

(o) 186 g S(C₃H₅)₂

Silber4 3.025.AP.

Iron reacts slowly with oxygen and water to form a compound commonly called rust (Fe₂O₃ · 4 H₂O).

(a) For 62.6 kg rust, calculate the moles of compound.

[2.70e+02] mol
(b) Find the moles of Fe₂O₃.

[2.70e+02] mol
(c) Determine the grams of iron.

[30200] g

Silber4 3.025a.EOCP.

Iron reacts slowly with oxygen and water to form a compound commonly called rust (Fe₂O₃ · 4 H₂O). Calculate the moles of Fe₂O₃ · 4 H₂O in 65.2 kg of rust.

(_) 2.81 mol Fe₂O₃ · 4 H₂O

(_) 28.1 mol Fe₂O₃ · 4 H₂O

(_) 0.281 mol Fe₂O₃ · 4 H₂O

(o) 281 mol Fe₂O₃ · 4 H₂O

Silber4 3.025b.EOCP.

Iron reacts slowly with oxygen and water to form a compound commonly called rust (Fe₂O₃ · 4 H₂O). Calculate the moles of Fe₂O₃in 65.2 kg of rust.

(_) 70.25 mol Fe₂O₃

(_) 7.02 mol Fe₂O₃

(_) 28.1 mol Fe₂O₃

(o) 281 mol Fe₂O₃

Silber4 3.025c.EOCP.

Iron reacts slowly with oxygen and water to form a compound commonly called rust (Fe₂O₃ · 4 H₂O). Calculate the grams of iron in 65.2 kg of rust.

(_) 2.81

10²g Fe

(_) 15.71 g Fe

(_) 31.42 g Fe

(o) 3.14

10⁴g Fe

Silber4 3.026.AP.

Propane (C₃H₈) is widely used in liquid form as a fuel for barbecue grills and camp stoves. For 67.7 g of propane, determine the following.

(a) Calculate the moles for of compound.

[1.54] mol
(b) Calculate the grams of carbon.

[55.3] g

Silber4 3.026a.EOCP.

Propane is widely used in liquid form as a fuel for barbecue grills and camp stoves. Calculate the moles of compound in 75.3 g of propane.

(_) 2.264

10³mol C₂H₆

(_) 3.32

10³mol C₃H₈

(o) 1.71 mol C₃H₈

(_) 2.504 mol C₂H₆

Silber4 3.026b.EOCP.

Propane is widely used in liquid form as a fuel for barbecue grills and camp stoves. Calculate the grams of carbon in 75.3 g of propane.

(_) 20.54 g C

(_) 74.00 g C

(o) 61.5 g C

(_) 30.1 g C

Silber4 3.027.EOCP.

The effectiveness of a nitrogen fertilizer is determined mainly by its mass % N. Which of the following fertilizers is most effective?

(_) potassium nitrate

(_) ammonium nitrate

(o) urea, CO(NH₂)₂

(_) ammonium sulfate

Silber4 3.028a.EOCP.

The mineral galena is composed of lead(II) sulfide and has an average density of 7.46 g/cm³. How many moles of lead(II) sulfide are in 1.00 ft³ of galena?

(_) 0.950 mol

(_) 1.12

10^-3 mol

(o) 883 mol

(_) 15.9 mol

Silber4 3.028b.EOCP.

The mineral galena is composed of lead(II) sulfide and has an average density of 7.46 g/cm³. How many lead atoms are in 1.00 dm³ of galena?

(_) 1.88

10¹⁸ atoms

(_) 1.88

10²³ atoms

(o) 1.88

10²⁵ atoms

(_) 5.18

10²³ atoms

Silber4 3.029.AP. ,

Hemoglobin, a protein found in red blood cells, carries O₂ from the lungs to the body's cells. Iron (as ferrous ion, Fe²⁺) makes up 0.33 mass % of hemoglobin. If the molar mass of hemoglobin is 6.8

10⁴ g/mol, how many Fe²⁺ ions are present in one molecule?
[4]

Silber4 3.029.EOCP.

10⁴ g/mol, how many Fe²⁺ ions are present in one molecule?

(_) 224 Fe²⁺ ions/molecule hemoglobin

(_) 120Fe²⁺ ions/molecule hemoglobin

(o) 4 Fe²⁺ ions/molecule hemoglobin

(_) 1218Fe²⁺ ions/molecule hemoglobin

Silber4 3.030.AP. ,

Select three ways compositional data may be given in a problem that involves finding an empirical formula.

[x] elemental composition

[x] combustion analysis

[x] mass % of electrons

[_] reaction states

Silber4 3.030.EOCP.

Which is not a way in which compositional data may be given in a problem to find an empirical formula?

(_) Determine the empirical formula from mass % of elements.

(_) Determine the empirical formula from elemental analysis.

(o) Determine the empirical formula from the number of elements in a compound.

(_) Determine the empirical formula from combustion analysis.

Silber4 3.031.EOCP.

Which of the following sets of information does not allow you to obtain the molecular formula of a covalent compound?

(_) mass % of each element and the total number of atoms in a molecule of the compound

(_) mass % of each element and the number of atoms of one element in a molecule of the compound

(o) number of moles of each type of atom in a given sample of the compound

(_) structural formula of the compound

Silber4 3.034.AP.

What is the empirical formula and empirical formula mass for each of the following compounds? (Type your answer using the format CH4 for CH₄.)

	empirical formula	empirical formula mass
(a) P₄O₁₀	[P2O5]	[141.96] g/mol
(b) C₄H₈	[CH2]	[14.03] g/mol
(c) C₃H₆O₃	[CH2O]	[30.03] g/mol
(d) S₄N₄	[SN]	[46.08] g/mol

Silber4 3.035.AP. ,

What is the molecular formula of each compound? (Type your answer using the format CO2 for CO₂.)

(a) CH₂ ( = 42.08 g/mol)
[C3H6]
(b) NH₂ ( = 32.05 g/mol)
[N2H4]
(c) NO₂ ( = 92.02 g/mol)
[N2O4]
(d) CHN ( = 135.14 g/mol)
[C5H5N5]

Silber4 3.036.AP.

What is the molecular formula of each compound? (Type your answer using the format C6H12O6 for C₆H₁₂O₆.)

(a) empirical formula CHCl (

= 84.93 g/mol)
[CH2Cl2]
(b) empirical formula CH₂Cl (

= 98.95 g/mol)
[C2H4Cl2]
(c) empirical formula CH (

= 78.11 g/mol)
[C6H6]
(d) empirical formula C₃H₆O₂ (

= 74.08 g/mol)
[C3H6O2]

Silber4 3.036d.EOCP.

Give the molecular formula for the compound below.

empirical formula C₇H₄O₂ (molar mass = 240.20 g/mol)

(_) C₇H₄O₂

(o) C₁₄H₈O₄

(_) CHO

(_) C₃H₂

Silber4 3.037.AP.

Determine the empirical formula of each of the following compounds. (Type your answer using the format CH4 for CH₄.)

(a) 0.088 mol chlorine atoms combined with 0.22 mol oxygen atoms
[Cl2O5]
(b) 3.37 g silicon combined with 12.4 g chlorine
[SiCl3]
(c) 27.3 mass % carbon and 72.7 mass % oxygen
[CO2]

Silber4 3.037a.EOCP.

Give the empirical formula for the compound formed by:

0.063 mol of chlorine atoms combined with 0.22 mol of oxygen atoms

(_) Cl₂O₅

(_) ClO

(_) ClO₂

(o) Cl₂O₇

Silber4 3.038.AP.

Determine the empirical formula of each of the following compounds. (Type your answer using the format CH4 for CH₄.)

(a) 0.039 mol iron atoms combined with 0.052 mol oxygen atoms
[Fe3O4]
(b) 0.903 g phosphorus combined with 6.99 g of bromine
[PBr3]
(c) a hydrocarbon with 79.9 mass % carbon
[CH3]

Silber4 3.038a.EOCP.

Give the empirical formula for the compound formed by:

0.039 mol of iron atoms combined with 0.052 mol of oxygen atoms

(_) Fe₂O₂

(_) Fe₄O₃

(_) FeO

(o) Fe₃O₄

Silber4 3.040.AP. ,

A chloride of silicon contains 79.1 mass % Cl. (Type your answer using the format CO2 for CO₂.)

(a) What is the empirical formula of the chloride?
[SiCl3]
(b) If the molar mass is 269 g/mol, what is the molecular formula?
[Si2Cl6]

Silber4 3.041a.EOCP.

A sample of 0.600 mol of a metal M reacts completely with excess fluorine to form 46.8 g of MF₂. How many moles of F are in the sample of MF₂ that forms?

(_) 2.0 mol F

(_) 0.600 mol F

(_) 1.0 mol F

(o) 1.20 mol F

Silber4 3.041b.EOCP.

A sample of 0.600 mol of a metal M reacts completely with excess fluorine to form 46.8 g of MF₂. How many grams of M are in this sample of MF₂

(_) 23 g M

(_) 8.80 g M

(_) 27.80 g M

(o) 24.0 g M

Silber4 3.041c.EOCP.

A sample of 0.600 mol of a metal M reacts completely with excess fluorine to form 46.8 g of MF₂. What element is represented by the symbol M?

(_) vanadium

(_) sodium

(_) titanium

(o) calcium

Silber4 3.042.AP. ,

A sample of 0.370 mol of a metal oxide (M₂O₃) weighs 55.4 g.

(a) How many moles of O are in the sample?

[1.11] mol
(b) How many grams of M are in the sample?

[37.6] g
(c) What element is represented by the symbol M?
[vanadium -or- V]

Silber4 3.043.AP. ,

Nicotine is a poisonous, addictive compound found in tobacco. A sample of nicotine contains 6.16 mmol C, 8.56 mmol H, and 1.23 mmol N [1 mmol (one millimole) = 10^-3 mol]. What is the empirical formula? (Type your answer using the format CH4 for CH₄.)
[C5H7N]

Silber4 3.043.EOCP.

Nicotine is a poisonous, addictive compound found in tobacco. A sample of nicotine contains 6.16 mmol of C, 8.56 mmol of H, and 1.23 mmol of N [1 mmol (1 millimole) = 10^-3 mol]. What is the empirical formula for nicotine?

(_) C₂H₅N

(o) C₅H₇N

(_) CHN

(_) CH₃N₂

Silber4 3.044.AP. ,

Cortisol (

= 362.47 g/mol), one of the major steroid hormones, is a key factor in the synthesis of protein. Its profound effect on the reduction of inflammation explains its use in the treatment of rheumatoid arthritis. Cortisol is 69.6% C, 8.34% H, and 22.1% O by mass. What is its molecular formula? (Type your answer using the format CO2 for CO₂.)
[C21H30O5]

Silber4 3.044.EOCP.

Cortisol (molar mass = 362.47 g/mol), one of the major steroid hormones, is a key factor in the synthesis of protein. Its profound effect on the reduction of inflammation explains its use in the treatment of rheumatoid arthritis. Cortisol is 69.6% C, 8.34% H, and 22.1% O by mass. What is its molecular formula?

(_) C₁₀H₁₅O₃

(o) C₂₁H₃₀O₅

(_) CHO

(_) C₆H₁₀O₂

Silber4 3.045.AP. ,

Acetaminophen is one of the most popular nonaspirin, "over-the-counter" pain relievers. What is the mass % of each element in acetaminophen?

C
[63.6]%
H
[6.01]%
N
[9.27]%
O
[21.2]%

Silber4 3.045a.EOCP.

Acetaminophen (below) is one of the most popular nonaspirin, "over-the-counter" pain relievers.

What is the mass % of oxygen in acetaminophen?

(_) 10.585 mass % O

(o) 21.17 mass % O

(_) 10.58 mass % O

(_) 16.00 mass % O

Silber4 3.045b.EOCP.

Acetaminophen (below) is one of the most popular nonaspirin, "over-the-counter" pain relievers.

What is the mass % of nitrogen in acetaminophen?

(_) 14.00 mass % N

(o) 9.268 mass % N

(_) 0.324 mass % N

(_) 18.54 mass % N

Silber4 3.045c.EOCP.

Acetaminophen (below) is one of the most popular nonaspirin, "over-the-counter" pain relievers.

What is the mass % of carbon in acetaminophen?

(_) 7.94 mass % C

(o) 63.56 mass % C

(_) 8 mass % C

(_) 12.01 mass % C

Silber4 3.045d.EOCP.

Acetaminophen (below) is one of the most popular nonaspirin, "over-the-counter" pain relievers.

What is the mass % of hydrogen in acetaminophen?

(_) 0.667 % H

(o) 6.002 % H

(_) 12.00 % H

(_) 0.7 % H

Silber4 3.046.AP. ,

Menthol (

= 156.3 g/mol), a strong-smelling substance used in cough drops, is a compound of carbon, hydrogen, and oxygen. When 0.1595 g menthol was subjected to combustion analysis, it produced 0.449 g CO₂ and 0.184 g H₂O. What is its molecular formula? (Type your answer using the format CO2 for CO₂.)
[C10H20O]

Silber4 3.046.EOCP.

Menthol (molar mass = 156.3 g/mol), a strong-smelling substance used in cough drops, is a compound of carbon, hydrogen, and oxygen. When 0.1595 g of menthol was subjected to combustion analysis, it produced 0.449 g of CO₂ and 0.184 g of H₂O. What is its molecular formula?

(_) CHO

(o) C₁₀H₂₀O

(_) C₁₆H₁₈O₈

(_) C₅H₈O₂

Silber4 3.047.AP.

What three types of information does a balanced chemical equation provide?

Key: The balanced reaction provides information on the amount and type of reactants and products.

How?

Key: The balanced reaction provides information in terms of molecules, mass and mass in grams.

Silber4 3.047.EOCP.

Which is not true about the types of information a balanced chemical equation provides?

(_) the identity of the reactant and products

(o) the empirical formulas of the reactants and products

(_) the physical states of the reactants and products

(_) the molar ratios of reactants and products expressed as coefficients

Silber4 3.049.EOCP.

The following boxes represent a chemical reaction between elements A (red) and B (green).

Which of the following best represents the balanced equation for the reaction?

(_) 2A + 2B

A₂ + B₂

(o) A₂ + B₂

2AB

(_) 4A₂ + 4B₂

8AB

(_) B₂ + 2A B

2B₂ + A₂

Silber4 3.049.EOCP.

In the process of balancing the equation:

Al + Cl₂

AlCl₃

Student I writes: Al + Cl₂

AlCl₂
Student II writes: Al + Cl₂ + Cl

AlCl₃
Student III writes: 2 Al + 3 Cl₂

2 AlCl₃

Which student has written the correct balanced chemical equation for the reaction?

(_) Student I

(_) Student II

(o) Student III

(_) all three students

Silber4 3.050.AP. ,

The following boxes represent a chemical reaction between elements A (red) and B (green): Which of the following best represents the balanced equation for the reaction?

(_) 2 A + 2 B

A₂ + B₂

(_) B₂ + 2 AB

2 B₂ + A₂

(o) A₂ + B₂

2 AB

(_) 4 A₂ + 4 B₂

8 AB

Silber4 3.051.AP. ,

Write balanced equations for each of the following by inserting the correct coefficients in the blanks. (Use the lowest possible coefficients.)

(a) [16]Cu(s) + [1]S₈(s) [8]Cu₂S(s)
(b) [1]P₄O₁₀(s) + [6]H₂O(l) [4]H₃PO₄(l)
(c) [1]B₂O₃(s) + [6]NaOH(aq) [2]Na₃BO₃(aq) + [3]H₂O(l)
(d) [4]CH₃NH₂(g) + [9]O₂(g) [4]CO₂(g) + [10]H₂O(g) + [2]N₂(g)

Silber4 3.051a.EOCP.

Give the correct balanced equation for the reaction below.

Cu(s) + S₈(s)

Cu₂S(s)

(_) 8 Cu(s) + S₈(s)

8 Cu₂S(s)

(_) 16 Cu(s) + 2 S₈(s)

16 Cu₂S(s)

(o) 16 Cu(s) + S₈(s)

8 Cu₂S(s)

(_) Cu(s) + S₈(s)

Cu₂S(s)

Silber4 3.051b.EOCP.

Give the correct balanced equation for the reaction below.

P₄O₁₀(s) + H₂O(l)

H₃PO₄(l)

(_) P₄O₁₀(s) + 3H₂O(l)

2 H₃PO₄(l)

(_) P₄O₁₀(s) + H₂O(l)

H₃PO₄(l)

(o) P₄O₁₀(s) + 6 H₂O(l)

4 H₃PO₄(l)

(_) 2 P₄O₁₀(s) + 3 H₂O(l)

2 H₃PO₄(l)

Silber4 3.051c.EOCP.

Give the correct balanced equation for the reaction below.

B₂O₃(s) + NaOH(aq)

Na₃BO₃(aq) + H₂O(l)

(_) B₂O₃(s) + NaOH(aq)

Na₃BO₃(aq) + H₂O(l)

(_) B₂O₃(s) + 2 NaOH(aq)

2 Na₃BO₃(aq) + H₂O(l)

(o) B₂O₃(s) + 6 NaOH(aq)

2 Na₃BO₃(aq) + 3 H₂O(l)

(_) 2 B₂O₃(s) + 3 NaOH(aq)

4 Na₃BO₃(aq) + H₂O(l)

Silber4 3.051d.EOCP.

Give the correct balanced equation for the reaction below.

CH₃NH₂(g) + O₂(g)

CO₂(g) + H₂O(g) + N₂(g)

(_) 2 CH₃NH₂(g) + 2 O₂(g)

2 CO₂(g) + 5 H₂O(g) + N₂(g)

(_) 3 CH₃NH₂(g) + O₂(g)

3 CO₂(g) + 2 H₂O(g) + 2 N₂(g)

(o) 4 CH₃NH₂(g) + 9 O₂(g)

4 CO₂(g) + 10H₂O(g) + 2 N₂(g)

(_) CH₃NH₂(g) + O₂(g)

CO₂(g) + H₂O(g) + N₂(g)

Silber4 3.052.AP. ,

Write (reduced) balanced equations for each of the following by inserting the correct coefficients in the blanks.

(a) [1]Cu(NO₃)₂(aq) + [2]KOH(aq) [1]Cu(OH)₂(s) + [2]KNO₃(aq)
(b) [1]BCl₃(g) + [3]H₂O(l) [1]H₃BO₃(s) + [3]HCl(g)
(c) [1]CaSiO₃(s) + [6]HF(g) [1]SiF₄(g) + [1]CaF₂(s) + [3]H₂O(l)
(d) [1](CN)₂(g) + [4]H₂O(l) [1]H₂C₂O₄(aq) + [2]NH₃(g)

Silber4 3.052a.EOCP.

Give the correct balanced equation for the reaction below.

Cu(NO₃)₂(aq) + KOH(aq)

Cu(OH)₂(s) + KNO₃(aq)

(_) Cu(NO₃)₂(aq) + KOH(aq)

Cu(OH)₂(s) + KNO₃(aq)

(_) 2 Cu(NO₃)₂(aq) + 4 KOH(aq)

2 Cu(OH)₂(s) + 4 KNO₃(aq)

(o) Cu(NO₃)₂(aq) + 2 KOH(aq)

Cu(OH)₂(s) + 2 KNO₃(aq)

(_) 2 Cu(NO₃)₂(aq) + KOH(aq)

2 Cu(OH)₂(s) + 2 KNO₃(aq)

Silber4 3.052b.EOCP.

Give the correct balanced equation for the reaction below.

BCl₃(g) + H₂O(l)

H₃BO₃(s) + HCl(g)

(_) 3 BCl₃(g) + 5 H₂O(l)

3 H₃BO₃(s) + HCl(g)

(_) 2 BCl₃(g) + 3 H₂O(l)

2 H₃BO₃(s) + 3 HCl(g)

(o) BCl₃(g) + 3 H₂O(l)

H₃BO₃(s) + 3 HCl(g)

(_) BCl₃(g) + H₂O(l)

H₃BO₃(s) + HCl(g)

Silber4 3.052c.EOCP.

Give the correct balanced equation for the reaction below.

CaSiO₃(s) + HF(g)

SiF₄(g) + CaF₂(s) + H₂O(l)

(_) CaSiO₃(s) + HF(g)

SiF₄(g) + CaF₂(s) + H₂O(l)

(_) CaSiO₃(s) + 6 HF(g)

2 SiF₄(g) + CaF₂(s) + 3 H₂O(l)

(o) CaSiO₃(s) + 6 HF(g)

SiF₄(g) + CaF₂(s) + 3 H₂O(l)

(_) 2 CaSiO₃(s) + 2 HF(g)

2 SiF₄(g) + 2 CaF₂(s) + H₂O(l)

Silber4 3.052d.EOCP.

Give the correct balanced equation for the reaction below.

(CN)₂(g) + H₂O(l)

H₂C₂O₄(aq) + NH₃(g)

(_) (CN)₂(g) + 2 H₂O(l)

H₂C₂O₄(aq) + 2 NH₃(g)

(_) (CN)₂(g) + H₂O(l)

H₂C₂O₄(aq) + NH₃(g)

(o) (CN)₂(g) + 4 H₂O(l)

H₂C₂O₄(aq) + 2 NH₃(g)

(_) 2(CN)₂(g) + 2 H₂O(l)

2 H₂C₂O₄(aq) + NH₃(g)

Silber4 3.053.AP. ,

Write balanced equations for each of the following by inserting the correct coefficients in the blanks. (Use the lowest possible coefficients.)

(a) [2]SO₂(g) + [1]O₂(g) [2]SO₃(g)
(b) [1]Sc₂O₃(s) + [3]H₂O(l) [2]Sc(OH)₃(s)
(c) [1]H₃PO₄(aq) + [2]NaOH(aq) [1]Na₂HPO₄(aq) + [2]H₂O(l)
(d) [1]C₆H₁₀O₅(s) + [6]O₂(g) [6]CO₂(g) + [5]H₂O(g)

Silber4 3.053a.EOCP.

Give the correct balanced equation for the reaction below.

SO₂(g) + O₂(g)

SO₃(g)

(_) 4 SO₂(g) + 2 O₂(g)

4 SO₃(g)

(_) SO₂(g) + 3 O₂(g)

2 SO₃(g)

(o) 2 SO₂(g) + O₂(g)

2 SO₃(g)

(_) SO₂(g) + O₂(g)

SO₃(g)

Silber4 3.053b.EOCP.

Give the correct balanced equation for the reaction below.

Sc₂O₃(s) + H₂O(l)

Sc(OH)₃(s)

(_) Sc₂O₃(s) + H₂O(l)

Sc(OH)₃(s)

(_) Sc₂O₃(s) + H₂O(l)

2 Sc(OH)₃(s)

(o) Sc₂O₃(s) + 3 H₂O(l)

2 Sc(OH)₃(s)

(_) 2 Sc₂O₃(s) + 6 H₂O(l)

4 Sc(OH)₃(s)

Silber4 3.053c.EOCP.

Give the correct balanced equation for the reaction below.

H₃PO₄(aq) + NaOH(aq)

Na₂HPO₄(aq) + H₂O(l)

(_) 2 H₃PO₄(aq) + 4 NaOH(aq)

2 Na₂HPO₄(aq) + 4 H₂O(l)

(_) H₃PO₄(aq) + NaOH(aq)

Na₂HPO₄(aq) + H₂O(l)

(o) H₃PO₄(aq) + 2 NaOH(aq)

Na₂HPO₄(aq) + 2 H₂O(l)

(_) 2 H₃PO₄(aq) + 2 NaOH(aq)

Na₂HPO₄(aq) + 3 H₂O(l)

Silber4 3.053d.EOCP.

Give the correct balanced equation for the reaction below.

C₆H₁₀O₅(s) + O₂(g)

CO₂(g) + H₂O(g)

(_) C₆H₁₀O₅(s) + O₂(g)

CO₂(g) + H₂O(g)

(_) 2 C₆H₁₀O₅(s) + 12 O₂(g)

12 CO₂(g) + 10 H₂O(g)

(o) C₆H₁₀O₅(s) + 6 O₂(g)

6 CO₂(g) + 5H₂O(g)

(_) C₆H₁₀O₅(s) + 3 O₂(g)

6 CO₂(g) + 3 H₂O(g)

Silber4 3.054.AP. ,

Write (reduced) balanced equations for each of the following by inserting the correct coefficients in the blanks.

(a) [1]As₄S₆(s) + [9]O₂(g) [1]As₄O₆(s) + [6]SO₂(g)
(b) [2]Ca₃(PO₄)₂(s) + [6]SiO₂(s) + [10]C(s) [1]P₄(g) + [6]CaSiO₃(l) + [10]CO(g)
(c) [3]Fe(s) + [4]H₂O(g) [1]Fe₃O₄(s) + [4]H₂(g)
(d) [6]S₂Cl₂(l) + [16]NH₃(g) [1]S₄N₄(s) + [1]S₈(s) + [12]NH₄Cl(s)

Silber4 3.054a.EOCP.

Give the correct balanced equation for the reaction below.

As₄S₆(s) + O₂(g)

As₄O₆(g) + SO₂(g)

(o) As₄S₆(s) + 9 O₂(g)

As₄O₆(g) + 6 SO₂(g)

(_) As₄S₆(s) + 4 O₂(g)

As₄O₆(g) + 6 SO₂(g)

(_) 2 As₄S₆(s) + 15 O₂(g)

2 As₄O₆(g) + 12 SO₂(g)

(_) As₄S₆(s) + O₂(g)

As₄O₆(g) + SO₂(g)

Silber4 3.054b.EOCP.

Give the correct balanced equation for the reaction below.

Ca₃(PO₄)₂(s) + SiO₂(s) + C(s)

P₄(g) + CaSiO₃(l) + CO(g)

(o) 2 Ca₃(PO₄)₂(s) + 6 SiO₂(s) + 10 C(s)

P₄(g) + 6 CaSiO₃(l) + 10 CO(g)

(_) Ca₃(PO₄)₂(s) + SiO₂(s) + C(s)

P₄(g) + CaSiO₃(l) + CO(g)

(_) 3 Ca₃(PO₄)₂(s) + 4 SiO₂(s) + 32 C(s)

2 P₄(g) + 9 CaSiO₃(l) + 32 CO(g)

(_) Ca₃(PO₄)₂(s) + 3 SiO₂(s) + C(s)

P₄(g) + 3 CaSiO₃(l) + 2 CO(g)

Silber4 3.054c.EOCP.

Give the correct balanced equation for the reaction below.

Fe(s) + H₂O(g)

Fe₃O₄(s) + H₂(g)

(o) 3 Fe(s) + 4 H₂O(g)

Fe₃O₄(s) + 4 H₂(g)

(_) 2 Fe(s) + 4 H₂O(g)

Fe₃O₄(s) + H₂(g)

(_) Fe(s) + H₂O(g)

Fe₃O₄(s) + H₂(g)

(_) 6 Fe(s) + 8 H₂O(g)

2 Fe₃O₄(s) + 8 H₂(g)

Silber4 3.054d.EOCP.

Give the correct balanced equation for the reaction below.

S₂Cl₂(l) + NH₃(g)

S₄N₄(s) + S₈(s) + NH₄Cl(s)

(o) 6 S₂Cl₂(l) + 16 NH₃(g)

S₄N₄(s) + S₈(s) + 12 NH₄Cl(s)

(_) 2 S₂Cl₂(l) + 4 NH₃(g)

S₄N₄(s) + S₈(s) + 4 NH₄Cl(s)

(_) 2 S₂Cl₂(l) + NH₃(g)

S₄N₄(s) + S₈(s) + 2 NH₄Cl(s)

(_) S₂Cl₂(l) + NH₃(g)

S₄N₄(s) + S₈(s) + NH₄Cl(s)

Silber4 3.055.AP. ,

Convert the following into balanced equations. (Type your answer using the format CO2 for CO₂. Use the lowest possible coefficients.)

(a) When gallium metal is heated in oxygen gas, it melts and forms solid gallium(III) oxide.
[4] [Ga](s) + [3] [O2](g) [2] [Ga2O3](s)
(b) Liquid hexane burns in oxygen gas to form carbon dioxide gas and water vapor.
[2] [C6H14](l) + [19] [O2](g) [12] [CO2](g) + [14] H₂O(g)
(c) When solutions of calcium chloride and sodium phosphate are mixed, solid calcium phosphate forms and sodium chloride remains in solution.
[3] [CaCl2](g) + [2] [Na3PO4](aq) [1] [Ca3(PO4)2](s) + [6] [NaCl](aq)

Silber4 3.055a.EOCP.

Convert the following description into a balanced equation:

When gallium metal is heated in oxygen gas, it melts and forms solid gallium(III) oxide.

(o) 4 Ga(s) + 3 O₂(g)

2 Ga₂O₃(s)

(_) 3 Ga(s) + O₂(g)

Ga₃O₂(s)

(_) 2 Ga(s) + 3 O₂(g)

2 Ga₂O₃(s)

(_) Ga(s) + O(g)

GaO(s)

Silber4 3.055b.EOCP.

Convert the following description into a balanced equation:

Liquid hexane burns in oxygen gas to form carbon dioxide gas and water vapor.

(o) 2 C₆H₁₄(l) + 19 O₂(g)

12 CO₂(g) + 14 H₂O(g)

(_) C₇H₁₄(l) + 21 O₂(g)

7 CO₂(g) + 7 H₂O(g)

(_) C₇H₁₆(l) + 11 O₂(g)

7 CO₂(g) + 8 H₂O(g)

(_) C₆H₁₄(l) + 19 O₂(g)

6 CO₂(g) + 7 H₂O(g)

Silber4 3.055c.EOCP.

Convert the following description into a balanced equation:

When solutions of calcium chloride and sodium phosphate are mixed, solid calcium phosphate forms and sodium chloride remains in solution.

(o) 3 CaCl₂(aq) + 2 Na₃PO₄(aq)

Ca₃(PO₄)₂(s) + 6 NaCl(aq)

(_) 2 CaCl₂(aq) + 2 NaPO₃(aq)

2 CaPO₃(s) + 2 NaCl(s)

(_) 2 CaCl(aq) + Na₂PO₃(aq)

Ca₂PO₃ (s) + 2 NaCl(aq)

(_) 3 CaCl₂(aq) + Na₃PO₄(aq)

Ca₃(PO₄)₂(s) + 3 NaCl(s)

Silber4 3.056.AP. ,

Convert the following into balanced equations. (Type your answer using the format CO2 for CO₂. Use the lowest possible coefficients.)

(a) When lead(II) nitrate solution is added to potassium iodide solution, solid lead(II) iodide forms and potassium nitrate solution remains.
[1] [Pb(NO3)2](aq) + [2]KI(aq) [1] [PbI2](s) + [2] [KNO3](aq)
(b) Liquid disilicon hexachloride reacts with water to form solid silicon dioxide, hydrogen chloride gas, and hydrogen gas.
[1] [Si2Cl6](l) + [4]H₂O(l) [2] [SiO2](s) + [6]HCl(g) + [1] [H2](g)
(c) When nitrogen dioxide is bubbled into water, a solution of nitric acid forms and gaseous nitrogen monoxide is released.
[3] [NO2](g) + [1] [H2O](l) [2] [HNO3](aq) + [1] [NO](g)

Silber4 3.056a.EOCP.

Convert the following description into a balanced equation:

When lead(II) nitrate solution is added to potassium iodide solution, solid lead(II) iodide forms and potassium nitrate solution remains.

(_) PbNO₃(aq) + KI(aq)

PbI(s) + KNO₃(aq)

(_) 2 Pb(NO₃)₂(aq) + 4 KI(aq)

2 PbI₂(s) + 4 KNO₃(aq)

(_) Pb₃NO₂(aq) + 2 KI(aq)

Pb₃I₂(s) + 2 KNO₂(aq)

(o) Pb(NO₃)₂(aq) + 2 KI(aq)

PbI₂(s) + 2 KNO₃(aq)

Silber4 3.056b.EOCP.

Convert the following description into a balanced equation:

Liquid disilicon hexachloride reacts with water to form solid silicon dioxide, hydrogen chloride gas, and hydrogen gas.

(_) Si₂Cl₆(l) + 2 H₂O(l)

2 SiO₂(s) + 2 HCl(g) + H₂(g)

(_) Si₂Cl₇(l) + 4 H₂O(l)

2 SiO₂(s) + 2 HCl(g) + 2 H(g)

(_) SiCl₆(l) + 3 H₂O(l)

SiO₂(s) + 6 HCl(g) + H(g)

(o) Si₂Cl₆(l) + 4 H₂O(l)

2 SiO₂(s) + 6 HCl(g) + H₂(g)

Silber4 3.056c.EOCP.

Convert the following description into a balanced equation:

When nitrogen dioxide is bubbled into water, a solution of nitric acid forms and gaseous nitrogen monoxide is released.

(_) 2 NO₂(aq) + H₂O(l)

2 HNO₃(aq) + NO(g)

(_) 3 NO₂(g) + 6 H₂O(l)

6 H₂NO(aq) + N₂O(g)

(_) 2 NO₂(g) + H₂O(l)

2 HNO₂(aq) + 2 NO(g)

(o) 3 NO₂(g) + H₂O(l)

2 HNO₃(aq) + NO(g)

Silber4 3.060.AP. ,

Percent yields are generally calculated from mass quantities. Would the result be the same if mole quantities were used instead?

(o) yes

(_) no

Why? (Select all that apply.)

[_] The % yield will not be the same since mass and moles are not directly proportional.

[_] The yields (%) are sums of actual and theoretical value.

[x] The % yield will be same since mass and moles are directly proportional.

[x] The yields (%) are ratios of actual to theoretical value.

[x] Both can be expressed in mass or mole comparison.

Silber4 3.061.AP.

Chlorine gas can be made in the laboratory by the reaction of hydrochloric acid and manganese (IV) oxide.

4 HCl(aq) + MnO₂(s) MnCl₂(aq) + 2 H₂O(g) + Cl₂(g)

Consider the reaction of 2.44 mol HCl with excess MnO₂.

(a) How many moles of Cl₂ form?

[0.610] mol
(b) How many grams of Cl₂ form?

[43.2] g

Silber4 3.061a.EOCP.

Chlorine gas can be made in the laboratory by combining hydrochloric acid and manganese(IV) oxide according to the following reaction:

4 HCl(aq) + MnO₂(s)

MnCl₂(aq) + 2 H₂O(g) + Cl₂(g)

When 1.82 mol of HCl reacts with excess MnO₂, how many moles of Cl₂ form?

(_) 7.28 mol Cl₂

(_) 1.82 mol Cl₂

(_) 0.9 mol Cl₂

(o) 0.455 mol Cl₂

Silber4 3.061b.EOCP.

Chlorine gas can be made in the laboratory by combining hydrochloric acid and manganese(IV) oxide according to the following reaction:

4 HCl(aq) + MnO₂(s)

MnCl₂(aq) + 2 H₂O(g) + Cl₂(g)

When 1.82 mol of HCl reacts with excess MnO₂, how many grams of Cl₂ form?

(_) 516 g Cl₂

(_) 130 g Cl₂

(_) 63.81 g Cl₂

(o) 32.3 g Cl₂

Silber4 3.062.AP.

Bismuth oxide reacts with carbon to form bismuth metal.

Bi₂O₃(s) + 3 C(s) 2 Bi(s) + 3 CO(g)

(a) When 439 g Bi₂O₃ reacts with excess carbon, how many moles of Bi₂O₃ react?

[0.942] mol
(b) How many moles of Bi form?

[1.88] mol

Silber4 3.062a.EOCP.

Bismuth oxide reacts with carbon to form bismuth metal according to the following reaction:

Bi₂O₃(s) + 3 C(s)

Bi(s) + 3 CO(g)

When 352 g of Bi₂O₃ reacts with excess carbon, how many moles of Bi₂O₃ react?

(_) 1.51 mol Bi₂O₃

(_) 0.7554 mol Bi₂O₃

(_) 2 mol Bi₂O₃

(o) 0.755 mol Bi₂O₃

Silber4 3.062b.EOCP.

0.755 mole of bismuth oxide reacts with an excess of carbon to form bismuth metal according to the following reaction:

Bi₂O₃(s) + 3 C(s)

2 Bi(s) + 3 CO(g)

How many moles of Bi form?

(_) 2 mol Bi

(_) 0.755 mol Bi

(_) 0.7554 mol Bi

(o) 1.51 mol Bi

Silber4 3.063.AP.

Potassium nitrate decomposes on heating, producing potassium oxide and gaseous nitrogen and oxygen.

4 KNO₃(s) 2 K₂O(s) + 2 N₂(g) + 5 O₂(g)

(a) How many moles of KNO₃ must be heated to produce 93.0 kg oxygen?

[2330] mol
(b) How many grams of KNO₃ is this?

[2.35e+05] g

Silber4 3.063a.EOCP.

Potassium nitrate decomposes on heating, producing potassium oxide and gaseous nitrogen and oxygen according to the following reaction:

4 KNO₃(s)

2 K₂O(s) + 2 N₂(g) + 5 O₂(g)

To produce 88.6 kg of oxygen, how many moles of KNO₃ must be heated?

(_) 2.215 mol KNO₃

(_) 1.1

10⁴ mol KNO₃

(_) 2.77

10³ mol KNO₃

(o) 2.22

10³ mol KNO₃

Silber4 3.063b.EOCP.

Potassium nitrate decomposes on heating, producing potassium oxide and gaseous nitrogen and oxygen according to the following reaction:

4 KNO₃(s)

2 K₂O(s) + 2 N₂(g) + 5 O₂(g)

How many grams of KNO₃ must be heated to produce 88.6 kg of oxygen?

(_) 2.196

10¹ g KNO₃

(o) 2.24

10⁵ g KNO₃

(_) 1.11

10⁶ g KNO₃

(_) 2.2

10² g KNO₃

Silber4 3.064.AP.

Chromium(III) oxide reacts with hydrogen sulfide (H₂S) gas to form chromium(III) sulfide and water.

Cr₂O₃(s) + 3 H₂S(g) Cr₂S₃(s) + 3 H₂O(l)

(a) How many moles of Cr₂O₃ are required to produce 465 g of Cr₂S₃?

[2.32] mol
(b) How many grams of Cr₂O₃ are required?

[353] g

Silber4 3.064a.EOCP.

Chromium(III) oxide reacts with hydrogen sulfide (H₂S) gas to form chromium(III) sulfide and water according to the following reaction:

Cr₂O₃(s) + 3 H₂S(g)

Cr₂S₃(s) + 3 H₂O(l)

To produce 421 g of Cr₂S₃, how many moles of Cr₂O₃ are required?

(_) 2 mol Cr₂O₃

(o) 2.10 mol Cr₂O₃

(_) 2.81

10⁴ mol Cr₂O₃

(_) 6.3 mol Cr₂O₃

Silber4 3.064b.EOCP.

Chromium(III) oxide reacts with hydrogen sulfide (H₂S) gas to form chromium(III) sulfide and water according to the following reaction:

Cr₂O₃(s) + 3 H₂S(g)

Cr₂S₃(s) + 3 H₂O(l)

How many grams of Cr₂O₃ are required to produce 421 g of Cr₂S₃?

(_) 4.3

10⁶ g Cr₂O₃

(o) 320. g Cr₂O₃

(_) 957.6 g Cr₂O₃

(_) 1.85

10² g Cr₂O₃

Silber4 3.065.AP.

Calculate the mass of each product formed when 37.38 g diborane (B₂H₆) reacts with excess water.

B₂H₆(g) + H₂O(l) H₃BO₃(s) + H₂(g) [unbalanced]

H₃BO₃

[167.1] g
H₂

[16.34] g

Silber4 3.065a.EOCP.

33.61 g of diborane (B₂H₆) reacts with excess water according to the following unbalanced equation:

B₂H₆(g) + H₂O(l)

H₃BO₃(s) + H₂(g)

Calculate the mass of H₃BO₃ formed.

(_) 225.3 g H₃BO₃

(o) 150.2 g H₃BO₃

(_) 75 g H₃BO₃

(_) 1.21 g H₃BO₃

Silber4 3.065b.EOCP.

33.61 g of diborane (B₂H₆) reacts with excess water according to the following unbalanced equation:

B₂H₆(g) + H₂O(l)

H₃BO₃(s) + H₂(g)

Calculate the mass of H₂ formed.

(_) 7 g H₂

(o) 14.69 g H₂

(_) 7.347 g H₂

(_) 2.452 g H₂

Silber4 3.066.AP.

Calculate the mass of each product formed when 224 g of silver sulfide reacts with excess hydrochloric acid.

Ag₂S(s) + HCl(aq) AgCl(s) + H₂S(g) [unbalanced]

AgCl

[259] g
H₂S

[30.8] g

Silber4 3.066a.EOCP.

174 g of silver sulfide reacts with excess hydrochloric acid according to the following unbalanced equation:

Ag₂S(s) + HCl(aq)

AgCl(s) + H₂S(g)

Calculate the mass of AgCl formed.

(_) 302 g AgCl

(o) 201 g AgCl

(_) 2 g AgCl

(_) 100.6 g AgCl

Silber4 3.066b.EOCP.

174 g of silver sulfide reacts with excess hydrochloric acid according to the following unbalanced equation:

Ag₂S(s) + HCl(aq)

AgCl(s) + H₂S(g)

Calculate the mass of H₂S formed.

(_) 48 g H₂

(o) 23.9 g H₂

(_) 1.40 g H₂

(_) 1265 g H₂

Silber4 3.067.EOCP.

Elemental phosphorus occurs as tetratomic molecules, P₄. What mass of chlorine gas is needed for complete reaction with 355 g of phosphorus to form phosphorus pentachloride?

(_) 406.3 g Cl

(o) 2.03

10³ g Cl₂

(_) 102 g Cl

(_) 203.1 g Cl₂

Silber4 3.068.EOCP.

Elemental sulfur occurs as octatomic molecules, S₈. What mass of fluorine gas is needed for complete reaction with 17.8 g of sulfur to form sulfur hexafluoride?

(_) 21.09 g F₂

(o) 63.3 g F₂

(_) 240.4 g F

(_) 1.32 g F

Silber4 3.069a.EOCP.

Solid iodine trichloride is prepared by reaction between solid iodine and gaseous chlorine to form iodine monochloride crystals, followed by treatment with additional chlorine.

Give the overall balanced equation for the formation of iodine trichloride.

(_) I₂(s) + Cl₂(g)

ICl₃(s)

(o) I₂(s) + 3 Cl₂(g)

2 ICl₃(s)

(_) I₂(s) + Cl₂(g)

2 ICl(s)

(_) ICl(s) + Cl₂(g)

ICl₃(s)

Silber4 3.069b.EOCP.

I₂(s) + 3 Cl₂(g)

2 ICl₃(s)

How many grams of iodine are needed to prepare 31.4 kg of final product?

(_) 2.885

10¹ g I₂

(o) 1.71

10⁴ g I₂

(_) 3.4

10⁴ g I₂

(_) 7.97

10³ g I₂

Silber4 3.070.AP.

Lead can be prepared from galena [lead(II) sulfide] by first roasting in oxygen gas to form lead(II) oxide and sulfur dioxide. Heating the metal oxide with more galena forms the molten metal and more sulfur dioxide. (Type your answer using the format CO2 for CO₂. Use the lowest possible coefficients.)

(a) Write a balanced equation for each step.
[2] [PbS](s) + [3] [O2](g)

[2] [PbO](s) + [2] [SO2](g)
[2] [PbO](s) + [1]PbS(s)

[3] [Pb](l) + [1] [SO2](g)
(b) Write an overall balanced equation for the process.
[1] [PbS](s) + [1] [O2](g)

[1] [Pb](l) + [1] [SO2](g)
(c) How many metric tons of sulfur dioxide form for every metric ton of lead obtained?
[0.309] metric tons

Silber4 3.070a.EOCP.

Lead can be prepared from galena [lead(II) sulfide] by first roasting the galena in oxygen gas to form lead(II) oxide and sulfur dioxide. Heating the metal oxide with more galena forms the molten metal and more sulfur dioxide.

Give an overall balanced equation for the process.

(_) 2 PbO(s) + PbS(s)

3 Pb(l) + SO₂(g)

(_) 2 PbS(s) + 3O₂(g)

2 PbO(s) + 2SO₂(g)

(_) Pb₂S(s) + O₂(g)

2 Pb(l) + SO₂(g)

(o) PbS(s) + O₂(g)

Pb(l) + SO₂(g)

Silber4 3.070b.EOCP.

(_) 1.3

10⁴ metric tons SO₂

(_) 64.1 metric tons SO₂

(_) 3.233 metric ton SO₂

(o) 0.309 metric ton SO₂

Silber4 3.071a.EOCP.

Many metals react with oxygen gas to form the metal oxide. For example, calcium reacts as follows:

2 Ca(s) + O₂(g)

2 CaO(s)

You wish to calculate the mass of calcium oxide that can be prepared from 4.20 g of Ca and 2.80 g of O₂.

How many moles of CaO can be produced from the given mass of Ca?

(_) 0.1 mol CaO

(_) 0.1746 mol CaO

(_) 0.210 mol CaO

(o) 0.105 mol CaO

Silber4 3.071b.EOCP.

Many metals react with oxygen gas to form the metal oxide. For example, calcium reacts as follows:

2 Ca(s) + O₂(g)

2 CaO(s)

You wish to calculate the mass of calcium oxide that can be prepared from 4.20 g of Ca and 2.80 g of O₂.

How many moles of CaO can be produced in this experiment from the given mass of O₂?

(_) 0.09 mol CaO

(_) 0.438 mol CaO

(_) 0.044 mol CaO

(o) 0.175 mol CaO

Silber4 3.071c.EOCP.

Many metals react with oxygen gas to form the metal oxide. For example, calcium reacts as follows:

2 Ca(s) + O₂(g)

2 CaO(s)

You wish to calculate the mass of calcium oxide that can be prepared from 4.20 g of Ca and 2.80 g of O₂.

Which is the limiting reactant?

(_) calcium oxide

(_) oxygen

(_) not enough information to decide

(o) calcium

Silber4 3.071d.EOCP.

Many metals react with oxygen gas to form the metal oxide. For example, calcium reacts as follows:

2 Ca(s) + O₂(g)

2 CaO(s)

You wish to calculate the mass of calcium oxide that can be prepared from 4.20 g of Ca and 2.80 g of O₂.

How many grams of CaO can be produced?

(_) 267 g CaO

(_) 9.791 g CaO

(_) 534.1 g CaO

(o) 5.89 g CaO

Silber4 3.072.AP.

Metal hydrides react with water to form hydrogen gas and the metal hydroxide.

SrH₂(s) + 2 H₂O(l) Sr(OH)₂(s) + 2 H₂(g)

You wish to calculate the mass of hydrogen gas that can be prepared from 5.89 g of SrH₂ and 4.67 g of H₂O.

(a) How many moles of H₂ can be produced from the given mass of SrH₂?

[0.131] mol
(b) How many moles of H₂ can be produced from the given mass of H₂O?

[0.259] mol
(c) Which is the limiting reactant? (Type your answer using the format CO2 for CO₂.)
[SrH2]
(d) How many grams of H₂ can be produced?

[0.265] g

Silber4 3.072a.EOCP.

Metal hydrides react with water to form hydrogen gas and the metal hydroxide. For example,

SrH₂(s) + 2 H₂O(l)

Sr(OH)₂(s) + 2 H₂(g)

You wish to calculate the mass of hydrogen gas that can be prepared from 5.63 g of SrH₂ and 4.80 g of H₂O.

How many moles of H₂ can be produced from the given mass of SrH₂?

(_) 0.0535 mol H₂

(_) 0.062 mol H₂

(_) 0.11 mol H₂

(o) 0.126 mol H₂

Silber4 3.072b.EOCP.

Metal hydrides react with water to form hydrogen gas and the metal hydroxide. For example,

SrH₂(s) + 2 H₂O(l)

Sr(OH)₂(s) + 2 H₂(g)

You wish to calculate the mass of hydrogen gas that can be prepared from 5.63 g of SrH₂ and 4.80 g of H₂O.

How many moles of H₂ can be produced in this experiment from the given mass of H₂O?

(_) 0.53 mol H₂

(_) 0.312 mol H₂

(_) 2.556 mol H₂

(o) 0.266 mol H₂

Silber4 3.072c.EOCP.

Metal hydrides react with water to form hydrogen gas and the metal hydroxide. For example,

SrH₂(s) + 2 H₂O(l)

Sr(OH)₂(s) + 2 H₂(g)

You wish to calculate the mass of hydrogen gas that can be prepared from 5.63 g of SrH₂ and 4.80 g of H₂O.

Which is the limiting reactant?

(_) Sr(OH)₂

(_) H₂O

(_) H₂

(o) SrH₂

Silber4 3.072c.EOCP.

Metal hydrides react with water to form hydrogen gas and the metal hydroxide. For example,

SrH₂(s) + 2 H₂O(l)

Sr(OH)₂(s) + 2 H₂(g)

You wish to calculate the mass of hydrogen gas that can be prepared from 5.63 g of SrH₂ and 4.80 g of H₂O.

How many grams of H₂ can be produced?

(_) 0.536 g H₂

(_) 0.13 g H₂

(_) 0.27 g H₂

(o) 0.253 g H₂

Silber4 3.073a.EOCP.

685 g of iodine trichloride reacts with 117.4 g of water to form iodic acid (HIO₃), according to the following unbalanced reaction:

ICl₃ + H₂O

ICl + HIO₃ + HCl

Calculate the maximum number of moles of HIO₃ that can be produced from this reaction.

(_) 2.9 mol HIO₃

(_) 2.17 mol HIO₃

(_) 6.5 mol HIO₃

(o) 1.47 mol HIO₃

Silber4 3.073b.EOCP.

685 g of iodine trichloride reacts with 117.4 g of water to form iodic acid (HIO₃), according to the following unbalanced reaction:

ICl₃ + H₂O

ICl + HIO₃ + HCl

Calculate the maximum number of grams of HIO₃ that can be produced from this reaction.

(_) 510 g HIO₃

(_) 381.7 g HIO₃

(_) 1140 g HIO₃

(o) 258 g HIO₃

Silber4 3.073c.EOCP.

685 g of iodine trichloride reacts with 117.4 g of water to form iodic acid (HIO₃), according to the following unbalanced reaction:

ICl₃ + H₂O

ICl + HIO₃ + HCl

What mass of the excess reactant remains?

(_) 568 g excess ICl₃

(_) 80 g excess H₂O

(_) 79.5 g excess ICl₃

(o) 37.9 g excess H₂O

Silber4 3.074.AP.

Calculate the maximum number of moles and grams of H₂S that can form when 176 g aluminum sulfide reacts with 122 g water.

Al₂S₃ + H₂O Al(OH)₃ + H₂S [unbalanced]

[3.39] mol

[115] g
What mass of the excess reactant remains?

[7] g

Silber4 3.074a.EOCP.

158 g of aluminum sulfide reacts with 131 g of water according to the following unbalanced reaction:

Al₂S₃ + H₂O

Al(OH)₃ + H₂S

Calculate the maximum number of moles of H₂S that can be produced from this reaction.

(_) 3.6 mol H₂S

(_) 2.104 mol H₂S

(o) 3.16 mol H₂S

(_) 1.05 mol H₂S

Silber4 3.074b.EOCP.

158 g of aluminum sulfide reacts with 131 g of water according to the following unbalanced reaction:

Al₂S₃ + H₂O

Al(OH)₃ + H₂S

Calculate the maximum number of grams of H₂S that can be produced from this reaction.

(_) 122.7 g H₂S

(_) 72 g H₂S

(o) 108 g H₂S

(_) 35.79 g H₂S

Silber4 3.074c.EOCP.

158 g of aluminum sulfide reacts with 131 g of water according to the following unbalanced reaction:

Al₂S₃ + H₂O

Al(OH)₃ + H₂S

What mass of the excess reactant remains?

(_) 27 g excess Al₂S₃

(_) 100 g excess Al₂S₃

(o) 17 g excess H₂O

(_) 114 g excess H₂O

Silber4 3.075a.EOCP.

0.100 mol of carbon is burned in a closed vessel with 8.00 g of oxygen.

How many grams of carbon dioxide can be produced from this reaction?

(_) 8.81 g CO₂

(_) 0.004 g CO₂

(o) 4.40 g CO₂

(_) 2.2 g CO₂

Silber4 3.075b.EOCP.

0.100 mol of carbon is burned in a closed vessel with 8.00 g of oxygen.

Which reactant is in excess?

(_) carbon

(_) not enough information to decide

(o) oxygen

(_) carbon dioxide

Silber4 3.075c.EOCP.

0.100 mol of carbon is burned in a closed vessel with 8.00 g of oxygen.

How many grams of excess reactant remain after the reaction?

(_) 2.2 g excess CO₂

(_) not enough information to decide

(o) 4.80 g excess O₂

(_) 6.8 g excess C

Silber4 3.076a.EOCP.

A mixture of 0.0359 g of hydrogen and 0.0175 mol of oxygen in a closed container is sparked to initiate a reaction.

How many grams of water can form?

(_) 0.0178 g H₂O

(_) 0.6 g H₂O

(o) 0.321 g H₂O

(_) 0.28 g H₂O

Silber4 3.076b.EOCP.

A mixture of 0.0359 g of hydrogen and 0.0175 mol of oxygen in a closed container is sparked to initiate a reaction.

Which reactant is in excess?

(_) H₂

(_) not enough information to decide

(o) O₂

(_) H₂O

Silber4 3.076c.EOCP.

A mixture of 0.0359 g of hydrogen and 0.0175 mol of oxygen in a closed container is sparked to initiate a reaction.

How many grams of the excess reactant remain after the reaction?

(_) 0.018 g excess H₂

(_) not enough information to decide

(o) 0.275 g excess O₂

(_) 0.3 g excess H₂O

Silber4 3.077a.EOCP.

62.5 g of aluminum nitrite and 54.6 g of ammonium chloride react completely to form aluminum chloride, nitrogen, and water.

Calculate the mass of aluminum nitrite present after the reaction is complete.

(_) 62.5 g

(_) all reacted, none left

(o) 6.4 g

(_) 56 g

Silber4 3.077b.EOCP.

62.5 g of aluminum nitrite and 54.6 g of ammonium chloride react completely to form aluminum chloride, nitrogen, and water.

Calculate the mass of ammonium chloride present after the reaction is complete.

(_) 54.6 g

(_) 27.3 g

(o) all reacted, none left

(_) 14 g

Silber4 3.077c.EOCP.

62.5 g of aluminum nitrite and 54.6 g of ammonium chloride react completely to form aluminum chloride, nitrogen, and water.

Calculate the mass of aluminum chloride present after the reaction is complete.

(_) 136.0 g

(_) 15.1 g

(o) 45.3 g

(_) 271.9 g

Silber4 3.077d.EOCP.

62.5 g of aluminum nitrite and 54.6 g of ammonium chloride react completely to form aluminum chloride, nitrogen, and water.

Calculate the mass of nitrogen present after the reaction is complete.

(_) 9.5 g

(_) 1.62 g

(o) 28.6 g

(_) 57.16 g

Silber4 3.077e.EOCP.

62.5 g of aluminum nitrite and 54.6 g of ammonium chloride react completely to form aluminum chloride, nitrogen, and water.

Calculate the mass of water present after the reaction is complete.

(_) 18.4 g

(_) 3.1 g

(o) 36.8 g

(_) 6.127 g

Silber4 3.078.AP.

Calcium nitrate and ammonium fluoride react to form calcium fluoride, dinitrogen monoxide, and water vapor. What mass of each substance is present after 16.8 g of calcium nitrate and 16.52 g of ammonium fluoride react completely?

Ca(NO₃)₂

[0.00e+00] g
NH₄F

[8.94] g
CaF₂

[7.99] g
N₂O

[9.01] g
H₂O

[7.38] g

Silber4 3.078a.EOCP.

16.8 g of calcium nitrate and 17.50 g of ammonium fluoride react completely to form calcium fluoride, dinitrogen monoxide, and water vapor.

Calculate the mass of calcium nitrate present after the reaction is complete.

(_) 16.8 g

(_) 8 g

(o) all reacted, none left

(_) 0.10 g

Silber4 3.078b.EOCP.

16.8 g of calcium nitrate and 17.50 g of ammonium fluoride react completely to form calcium fluoride, dinitrogen monoxide, and water vapor.

Calculate the mass of ammonium fluoride present after the reaction is complete.

(_) 7.6 g

(_) all reacted, none left

(o) 9.95 g

(_) 18 g

Silber4 3.078c.EOCP.

16.8 g of calcium nitrate and 17.50 g of ammonium fluoride react completely to form calcium fluoride, dinitrogen monoxide, and water vapor.

Calculate the mass of calcium fluoride present after the reaction is complete.

(_) 15.93 g

(_) 3.98 g

(o) 7.96 g

(_) 32 g

Silber4 3.078d.EOCP.

16.8 g of calcium nitrate and 17.50 g of ammonium fluoride react completely to form calcium fluoride, dinitrogen monoxide, and water vapor.

Calculate the mass of dinitrogen monoxide present after the reaction is complete.

(_) 4.5 g

(_) 2.24 g

(o) 8.98 g

(_) 17.96 g

Silber4 3.078e.EOCP.

16.8 g of calcium nitrate and 17.50 g of ammonium fluoride react completely to form calcium fluoride, dinitrogen monoxide, and water vapor.

Calculate the mass of water vapor present after the reaction is complete.

(_) 1.8 g

(_) 0.9 g

(o) 7.35 g

(_) 3.68 g

Silber4 3.079.EOCP.

Two successive reactions, A

B and B

C, have yields of 82% and 65%, respectively. What is the overall percent yield for conversion of A to C?

(_) 82% overall yield

(_) 65% overall yield

(o) 53% overall yield

(_) 17% overall yield

Silber4 3.080.EOCP.

Two successive reactions, D

E and E

F, have yields of 48% and 73%, respectively. What is the overall percent yield for conversion of D to F?

(_) 48% overall yield

(_) 25% overall yield

(o) 35% overall yield

(_) 73% overall yield

Silber4 3.081.AP.

What is the percent yield of a reaction in which 41.6 g of tungsten (VI) oxide (WO₃) reacts with excess hydrogen gas to produce metallic tungsten and 9.70 mL of water (d = 1.00 g/mL)?

[1.00e+02]%

Silber4 3.081.EOCP.

What is the percent yield of a reaction in which 41.5 g of tungsten(VI) oxide (WO₃) reacts with excess hydrogen gas to produce metallic tungsten and 9.50 mL of water (d = 1.00 g/mL)?

(_) 50% yield

(_) 53.7% yield

(o) 98.2% yield

(_) 18% yield

Silber4 3.082.EOCP.

What is the percent yield of a reaction in which 200. g of phosphorus trichloride reacts with excess water to form 128 g of HCl and aqueous phosphorous acid (H₃PO₃)?

(_) 12.8% yield

(_) 16% yield

(o) 80.5% yield

(_) 53% yield

Silber4 3.083.EOCP.

When 18.5 g of methane and 43.0 g of chlorine gas undergo a reaction that has an 80.0% yield, what mass of chloromethane (CH₃Cl) forms? (Note: Hydrogen chloride also forms.)

(_) 30.59 g CH₃Cl

(_) 49 g CH₃Cl

(o) 24.5 g CH₃Cl

(_) 15.3 g CH₃Cl

Silber4 3.084.EOCP.

When 56.6 g of calcium and 30.5 g of nitrogen gas undergo a reaction that has a 93.0% yield, what mass of calcium nitride forms?

(_) 70.93 g CaN

(_) 44.6 g CaN₂

(o) 64.8 g Ca₃N₂

(_) 62 g Ca₂N₃

Silber4 3.085.AP.

Cyanogen, (CN)₂, has been observed in the atmosphere of Titan, Saturn's largest moon, and in the gases of interstellar nebulas. On Earth, it is used as a welding gas and a fumigant. In its reaction with fluorine gas, carbon tetrafluoride and nitrogen trifluoride gases are produced. What mass of carbon tetrafluoride forms when 70.9 g of each reactant is used?

[46.9] g

Silber4 3.085.EOCP.

(_) 185 g CF₄

(_) 175.9 g CF₄

(o) 52.9 g CF₄

(_) 648 g CF₄

Silber4 3.086.EOCP.

An intermediate step in the industrial production of nitric acid involves the reaction of ammonia with oxygen gas to form nitrogen monoxide and water. How many grams of nitrogen monoxide can form by the reaction of 466 g of ammonia with 812 g of oxygen?

(_) 761.5 g NO

(_) 950 g NO

(o) 609 g NO

(_) 101.5 g NO

Silber4 3.087a.EOCP.

Gaseous butane is compressed and used as a liquid fuel in disposable cigarette lighters and lightweight camping stoves. Suppose a lighter contains 6.50 mL of butane (d = 0.579 g/mL).

How many grams of oxygen are needed to burn the butane completely?

(_) 2.07 g O₂

(_) 3.6 g O₂

(o) 13.5 g O₂

(_) 12.43 g O₂

Silber4 3.087b.EOCP.

(_) 3.8 mol CO₂

(_) 0.004 mol CO₂

(_) 26 mol CO₂

(o) 0.259 mol CO₂

Silber4 3.087c.EOCP.

Gaseous butane is compressed and used as a liquid fuel in disposable cigarette lighters and lightweight camping stoves. Suppose a lighter contains 6.50 mL of butane (d = 0.579 g/mL).

How many total molecules of gas form when the butane burns completely?

(_) 3.9

10²² gas molecules

(_) 1.95

10²³ gas molecules

(_) 1.6

10²³ gas molecules

(o) 3.51

10²³ gas molecules

Silber4 3.088.EOCP.

Sodium borohydride (NaBH₄) can be prepared by reacting sodium hydride with gaseous diborane (B₂H₆). Assuming a 95.5% yield, how many grams of NaBH₄ can be prepared by reacting 7.88 g of sodium hydride and 8.12 g of diborane?

(_) 34.6 g

(_) 22.2 g

(_) 12.4 g

(o) 11.9 g

Silber4 3.089a.EOCP.

Box A represents a unit volume of a solution.

Box B represents the same unit volume of solution that has:

(_) more solute added and lower concentration.

(_) more solute added and higher molarity.

(_) more solute added and lower concentration.

(o) more solvent added and lower concentration.

Silber4 3.089b.EOCP.

Box A represents a unit volume of a solution.

Box C represents the same unit volume of solution that has:

(_) more solute added and lower concentration.

(_) more solvent added and lower concentration.

(_) more solute added and lower concentration.

(o) more solute added and higher molarity.

Silber4 3.091.AP.

Are the following instructions for diluting a 10.0 M solution to a 1.00 M solution correct: "Take 100.0 mL of the 10.0 M solution and add 900.0 mL water"?

(_) yes

(o) no

Explain.

Key: Volumes are not additive. Take 100.00 mL of the 10.0 M solution and add sufficient water to make 1.00 L of solution.

Silber4 3.092.AP.

Calculate each of the following quantities.

(a) grams of solute in 167.7 mL of 0.207 M calcium acetate

[5.49] g
(b) molarity of 512 mL solution containing 21.1 g of potassium iodide

[0.248] M
(c) moles of solute in 145.6 L of 0.743 M sodium cyanide

[108] mol

Silber4 3.092a.EOCP.

Calculate the grams of solute in 175.8 mL of 0.207 M calcium acetate.

(o) 5.76 g Ca(CH₃COO)₂

(_) 0.04 g Ca(CH₃COO)₂

(_) 32.7 g Ca(CH₃COO)₂

(_) 186.2 g Ca(CH₃COO)₂

Silber4 3.093.AP.

Calculate each of the following quantities.

(a) volume in liters of 1.71 M potassium hydroxide that contains 7.90 g of solute

[0.0823] L
(b) number of Cu²⁺ ions in 65 L of 3.0 M copper(II) chloride

[1.2e+26] ions
(c) molarity of a 296 mL of solution containing 100. mmol of glucose

[0.338] M

Silber4 3.093b.EOCP.

Calculate the number of Cu²⁺ ions in 52 L of 2.3 M copper(II) chloride.

(o) 7.2

10²⁵Cu²⁺ ions

(_) 1.36

10²⁵Cu²⁺ ions

(_) 3.6

10²⁵Cu²⁺ ions

(_) 1.44

10²⁶Cu²⁺ ions

Silber4 3.094.AP.

Calculate each of the following quantities.

(a) grams of solute needed to make 427 mL of 5.62

10^-2 M potassium sulfate

[4.18] g
(b) molarity of a solution that contains 6.26 mg of calcium chloride in each milliliter

[0.0564] M
(c) number of Mg²⁺ ions in each milliliter of 0.246 M magnesium bromide

[1.48e+20] ions

Silber4 3.094a.EOCP.

Calculate the grams of solute needed to make 475 mL of 5.62

10^-2 M potassium sulfate.

(o) 4.65 g K₂SO₄

(_) 4.7

10³g K₂SO₄

(_) 26.70 g K₂SO₄

(_) 0.48 g K₂SO₄

Silber4 3.094b.EOCP.

Calculate the molarity of a solution that contains 6.55 mg of calcium chloride in each milliliter.

(o) 5.90

10^-2 M CaCl₂

(_) 5.9 M CaCl₂

(_) 7.269

10^-1 M CaCl₂

(_) 1.7

10^-2 M CaCl₂

Silber4 3.094c.EOCP.

Calculate the number of Mg²⁺ ions in each milliliter of 0.184 M magnesium bromide.

(o) 1.11

10²⁰Mg²⁺ ions

(_) 1.1

10²³Mg²⁺ ions

(_) 1.84

10^-4Mg²⁺ ions

(_) 2

10²⁶Mg²⁺ ions

Silber4 3.095.AP.

Calculate each of the following quantities.

(a) molarity of the solution resulting from dissolving 34.4 g of silver nitrate in enough water to give a final volume of 326 mL

[0.621] M
(b) volume in liters of 0.489 M manganese(II) sulfate that contains 55.0 g of solute

[0.745] L
(c) volume in milliliters of 6.58

10^-2 M adenosine triphosphate (ATP) that contains 1.41 mmol ATP

[21.4] mL

Silber4 3.095a.EOCP.

Calculate the molarity of the solution resulting from dissolving 46.0 g of silver nitrate in enough water to give a final volume of 335 mL.

(_) 15.41 M AgNO₃

(_) 1.237 M AgNO₃

(_) 11 M AgNO₃

(o) 0.808 M AgNO₃

Silber4 3.095b.EOCP.

Calculate the volume in liters of 0.385 M manganese(II) sulfate that contains 57.0 g of solute.

(_) 148 L MnSO₄

(_) 1.020 L MnSO₄

(_) 0.007 L MnSO₄

(o) 0.980 L MnSO₄

Silber4 3.095c.EOCP.

Calculate the volume in milliliters of 6.44

10^-2 M adenosine triphosphate (ATP) that contains 1.68 mmol of ATP.

(_) 108 mL ATP

(_) 38.33 mL ATP

(_) 2.6

10^-2mL ATP

(o) 26.1 mL ATP

Silber4 3.096.AP.

Calculate each of the following quantities.

(a) molarity of a solution prepared by diluting 30.44 mL of 0.288 M potassium chloride to 150.00 mL

[0.0584] M
(b) molarity of a solution prepared by diluting 26.46 mL of 0.0626 M ammonium sulfate to 500.00 mL

[0.00331] M
(c) molarity of sodium ion in a solution made by mixing 4.42 mL of 0.265 M sodium chloride with 500. mL of 6.51

10^-3 M sodium sulfate (assume volumes are additive)

[0.0152] M

Silber4 3.096a.EOCP.

Calculate the molarity of a solution prepared by diluting 37.00 mL of 0.250 M potassium chloride to 150.00 mL.

(_) 1.37 M KCl

(_) 1.82 M KCl

(_) 0.05142 M KCl

(o) 0.0617 M KCl

Silber4 3.096b.EOCP.

Calculate the molarity of a solution prepared by diluting 25.71 mL of 0.0706 M ammonium sulfate to 500.00 mL.

(_) 1.373 M (NH₄)₂SO₄

(_) 0.0514 M (NH₄)₂SO₄

(_) 0.73 M (NH₄)₂SO₄

(o) 0.00363 M (NH₄)₂SO₄

Silber4 3.096c.EOCP.

Calculate the molarity of sodium ion in a solution made by mixing 3.58 mL of 0.288 M sodium chloride with 500. mL of 6.51

10^-3 M sodium sulfate (assume volumes are additive).

(_) 1.5

10^-5M Na⁺

(_) 6.51 M Na⁺

(_) 1.031 M Na⁺

(o) 0.0150 M Na⁺

Silber4 3.097.AP.

Calculate each of the following quantities.

(a) volume of 1.549 M copper(II) nitrate that must be diluted with water to prepare 776.3 mL of a 0.8543 M solution

[428.1] mL
(b) volume of 1.35 M calcium chloride that must be diluted with water to prepare 269 mL of a 2.78

10^-2 M chloride ion solution

[2.77] mL
(c) final volume of a 0.0633 M solution prepared by diluting 21.0 mL of 0.155 M lithium carbonate with water

[51.4] mL

Silber4 3.097a.EOCP.

Calculate the volume of 2.050 M copper(II) nitrate that must be diluted with water to prepare 750.0 mL of a 0.8543 M solution.

(_) 2.400 mL Cu(NO₃)₂

(_) 366 mL Cu(NO₃)₂

(o) 312.5 mL Cu(NO₃)₂

(_) 640.7 mL Cu(NO₃)₂

Silber4 3.097b.EOCP.

Calculate the volume of 1.03 M calcium chloride that must be diluted with water to prepare 350. mL of a 2.66

10^-2 M chloride ion solution.

(_) 0.2213 mL CaCl₂

(_) 9.039 mL CaCl₂

(o) 4.52 mL CaCl₂

(_) 18.1 mL CaCl₂

Silber4 3.097c.EOCP.

Calculate the final volume of a 0.0700 M solution prepared by diluting 18.0 mL of 0.155 M lithium carbonate with water.

(_) 116.1 mL Li₂CO₃

(_) 257 mL Li₂CO₃

(o) 39.9 mL Li₂CO₃

(_) 20.21 mL Li₂CO₃

Silber4 3.098.AP. ,

A sample of concentrated nitric acid has a density of 1.41 g/mL and contains 70.0% HNO₃ by mass.

(a) What mass of HNO₃ is present per liter of solution?

[2.77] g
(b) What is the molarity of the solution?

[15.7] M

Silber4 3.098a.EOCP.

A sample of concentrated nitric acid has a density of 1.41 g/mL and contains 70.0% HNO₃ by mass.

What mass of HNO₃ is present per liter of solution?

(_) 496.4 g HNO₃

(_) 0.987 g HNO₃

(o) 987 g HNO₃

(_) 2014 g HNO₃

Silber4 3.098b.EOCP.

A sample of concentrated nitric acid has a density of 1.41 g/mL and contains 70.0% HNO₃ by mass.

What is the molarity of the HNO₃ solution?

(_) 7.9 M HNO₃

(_) 0.016 M HNO₃

(o) 15.7 M HNO₃

(_) 31.96 M HNO₃

Silber4 3.099a.EOCP.

Concentrated sulfuric acid (18.3 M) has a density of 1.84 g/mL.

How many moles of sulfuric acid are present per milliliter of solution?

(_) 3.4

10^-2 mol H₂SO₄/mL

(_) 33.7 mol H₂SO₄/mL

(o) 1.83

10^-2 mol H₂SO₄/mL

(_) 1.005

10^-1 mol H₂SO₄/mL

Silber4 3.099b.EOCP.

Concentrated sulfuric acid (18.3 M) has a density of 1.84 g/mL.

What is the mass % of H₂SO₄ in the solution?

(_) 1.025 mass % H₂SO₄

(_) 17.95 mass % H₂SO₄

(o) 97.6 mass % H₂SO₄

(_) 0.98 mass % H₂SO₄

Silber4 3.100.AP.

How many milliliters of 0.55 M HCl are needed to react with 6.9 g of CaCO₃?

2 HCl(aq) + CaCO₃(s) CaCl₂(aq) + CO₂(g) + H₂O(l)

[250] mL

Silber4 3.100.EOCP.

How many milliliters of 0.383 M HCl are needed to react with 16.2 g of CaCO₃ according to the following reaction?

2 HCl(aq) + CaCO₃(s)

CaCl₂(aq) + CO₂(g) + H₂O(l)

(_) 4

10⁴ mL HCl

(_) 0.1240 mL HCl

(o) 8.45

10² mL HCl

(_) 42.3 mL HCl

Silber4 3.101.AP.

How many grams of NaH₂PO₄ are needed to react with 43.81 mL of 0.285 M NaOH?

NaH₂PO₄(s) + 2 NaOH(aq) Na₃PO₄(aq) + 2 H₂O(l)

[0.749] g

Silber4 3.101.EOCP.

How many grams of NaH₂PO₄ are needed to react with 38.74 mL of 0.275 M NaOH according to the following reaction?

NaH₂PO₄(s) + 2 NaOH(aq)

Na₃PO₄(aq) + 2 H₂O(l)

(_) 1.28 g NaH₂PO₄

(_) 1278 g NaH₂PO₄

(o) 0.639 g NaH₂PO₄

(_) 25.6 g NaH₂PO₄

Silber4 3.102.EOCP.

How many grams of solid barium sulfate form when 25.0 mL of 0.160 M barium chloride reacts with 68.0 mL of 0.055 M sodium sulfate? (Aqueous sodium chloride is the other product).

(_) 2.5 g BaSO₄

(_) 0.934 g BaSO₄

(o) 0.87 g BaSO₄

(_) 0.321 g BaSO₄

Silber4 3.103.EOCP.

How many moles of which reactant are in excess when 350.0 mL of 0.210 M sulfuric acid reacts with 0.500 L of 0.196 M sodium hydroxide to form water and aqueous sodium sulfate?

(_) 4.9

10^-2 mol H₂SO₄

(_) 7.35

10^-2 mol H₂SO₄

(o) 2.45

10^-2 mol H₂SO₄

(_) 9.8

10^-2 mol H₂SO₄

Silber4 3.104.EOCP.

Ordinary household bleach is an aqueous solution of sodium hypochlorite. What is the molarity of a bleach solution that contains 20.5 g of sodium hypochlorite in a total volume of 375 mL?

(_) 0.5722 M NaClO

(_) 0.27 M NaClO

(o) 0.734 M NaClO

(_) 7.7 M NaClO

Silber4 3.105a.EOCP.

Muriatic acid, an industrial grade of concentrated HCl, is used to clean masonry and etch cement for painting. Its concentration is 11.7 M.

Calculate the volume in milliliters of muriatic acid needed to make 5.0 gallons of 3.5 M acid for routine use (1 gal = 4 qt; 1 qt = 0.946 L).

(_) 41 mL muriatic acid

(_) 1.50 mL muriatic acid

(o) 5.7

10³ mL muriatic acid

(_) 1.89

10⁴ mL muriatic acid

Silber4 3.105b.EOCP.

Muriatic acid, an industrial grade of concentrated HCl, is used to clean masonry and etch cement for painting. Its concentration is 11.7 M.

How many milliliters of the muriatic acid solution contain 9.55 g of HCl?

(_) 816 mL muriatic acid

(_) 3.1 mL muriatic acid

(o) 22.4 mL muriatic acid

(_) 4.074 mL muriatic acid

Silber4 3.106.AP.

A sample of impure magnesium was analyzed by allowing it to react with excess HCl solution, as shown below.

Mg(s) + 2 HCl(aq) MgCl₂(aq) + H₂(g)

After 1.69 g of the impure metal was treated with 0.100 L of 0.768 M HCl, 0.0125 mol HCl remained. Assuming the impurities do not react with the acid, what is the mass % Mg in the sample?

[46.3]%

Silber4 3.106.EOCP.

A sample of impure magnesium was analyzed by allowing it to react with excess HCl solution according to the following reaction:

Mg(s) + 2 HCl(aq)

MgCl₂(aq) + H₂(g)

After 1.32 g of the impure metal was treated with 0.100 L of 0.750 M HCl, 0.0125 mol of HCl remained. Assuming the impurities do not react with the acid, what is the mass % Mg in the sample?

(o) 57.5 mass % Mg

(_) 6.25 mass % Mg

(_) 1.51 mass % Mg

(_) 76.0 mass % Mg

Silber4 3.108.AP. ,

The study of sulfur-nitrogen compounds is an active area of chemical research, made more so by the discovery in the early 1980s of one such compound that conducts electricity like a metal. The first sulfur-nitrogen compound was prepared in 1835 and serves today as a reactant for preparing many of the others. Mass spectrometry of the compound shows a molar mass of 184.27 g/mol, and analysis shows it to contain 2.288 g of S for every 1.000 g of N. What is its molecular formula? (Type your answer using the format CO2 for CO₂.)
[S4N4]

Silber4 3.108.EOCP.

(o) S₄N₄

(_) S₃N₂

(_) S₂N₃

(_) S₆N₆

Silber4 3.109.EOCP.

Narceine is a narcotic in opium. It crystallizes from water solution as a hydrate that contains 10.8 mass % water. If the molar mass of narceine hydrate is 499.52 g/mol, determine x in narceine · xH₂O.

(o) 3

(_) 2

(_) 5

(_) 6

Silber4 3.110.AP. ,

Hydrogen-containing fuels have a "fuel value" based on their mass % H. Rank the following compounds from highest mass % H to lowest: ethane, propane, benzene, ethanol, cetyl palmitate (whale oil, C₃₂H₆₄O₂).

ethane	[ 1 (lowest mass) ]
propane	[ 2 ]
benzene	[ 5 (highest mass) ]
ethanol	[ 4 ]
cetyl palmitate	[ 3 ]

Silber4 3.110.EOCP.

Hydrogen-containing fuels have a "fuel value" based on their mass % H. Which of the following compounds contains the highest mass % H?

(o) ethane

(_) propane

(_) benzene

(_) ethanol

Silber4 3.111.AP. ,

Serotonin (

= 176 g/mol) is a compound that conducts nerve impulses in brain and muscle. It contains 68.2 mass % C, 6.86 mass % H, 15.9 mass % N, and 9.08 mass % O. What is its molecular formula? (Type your answer using the format CH4 for CH₄.)
[C10H12N2O]

Silber4 3.111.EOCP.

Serotonin (molar mass = 176 g/mol) is a compound that conducts nerve impulses in brain and muscle. It contains 68.2 mass % C, 6.86 mass % H, 15.9 mass % N, and 9.08 mass % O. What is its molecular formula?

(o) C₁₀H₁₂N₂O

(_) C₂₀H₃₀N₃O₃

(_) C₁₂H₁₀NO₂

(_) C₅H₆NO₂

Silber4 3.112.AP. ,

Convert the following descriptions of reactions into balanced equations. (Type your answer using the format CO2 for CO₂. Use the lowest possible coefficients.)

(a) In a gaseous reaction, hydrogen sulfide burns in oxygen to form sulfur dioxide and water vapor.
[2] [H2S](g) + [3]O₂(g) [2] [SO2](g) + [2]H₂O(g)
(b) When crystalline potassium chlorate is heated to just above its melting point, it reacts to form two different crystalline compounds, potassium chloride and potassium perchlorate.
[4] [KClO3](s) [1]KCl(s) + [3] [KClO4](s)
(c) When hydrogen gas is passed over powdered iron(III) oxide, iron metal and water vapor form.
[3] [H2](g) + [1] [Fe2O3](s) [2] [Fe](s) + [3] [H2O](g)
(d) The combustion of gaseous ethane in air forms carbon dioxide and water vapor.
[2] [C2H6](g) + [7]O₂(g) [4] [CO2](g) + [6]H₂O(g)
(e) Iron(II) chloride can be converted to iron(III) fluoride by treatment with chlorine trifluoride gas. Chlorine gas is also formed.
[2] [FeCl2](s) + [2] [ClF3](g) [2] [FeF3](s) + [3] [Cl2](g)

Silber4 3.112a.EOCP.

Convert the following description of the reaction into a balanced equation.

In a gaseous reaction, hydrogen sulfide burns in oxygen to form sulfur dioxide and water vapor.

(_) 2 H₂S(s) + O₂(g)

2 SO₂(g) + 2 H₂O(g)

(_) 2 HS(s) + O₂(g)

S₂O(g) + H₂O(g)

(o) 2 H₂S(s) + 3 O₂(g)

2 SO₂(g) + 2 H₂O(g)

(_) 4 HS(s) + 5 O₂(g)

4 SO₂(g) + 2 H₂O(g)

Silber4 3.112b.EOCP.

Convert the following description of the reaction into a balanced equation.

When crystalline potassium chlorate is heated to just above its melting point, it reacts to form two different crystalline compounds, potassium chloride and potassium perchlorate.

(_) 2 KClO(s)

KCl(s) + KClO₂(s)

(_) 6 KClO₄(s)

3 KCl(s) + 3 KClO₃(s)

(o) 4 KClO₃(s)

KCl(s) + 3 KClO₄(s)

(_) 2 KClO₃(s)

KCl(s) + KClO₄(s)

Silber4 3.112c.EOCP.

Convert the following description of the reaction into a balanced equation.

When hydrogen gas is passed over powdered iron(III) oxide, iron metal and water vapor form.

(_) 3 H₂(g) + Fe₂O₃(s)

Fe₂(s) + 3 H₂O(g)

(_) 3 H₂(g) + 2 Fe₂O₃(s)

2 Fe(s) + 3 H₂O(g)

(o) 3 H₂(g) + Fe₂O₃(s)

2 Fe(s) + 3 H₂O(g)

(_) 6 H(g) + Fe₃O₂(s)

3 Fe(s) + 3 H₂O(g)

Silber4 3.112d.EOCP.

Convert the following description of the reaction into a balanced equation.

The combustion of gaseous ethane in air forms carbon dioxide and water vapor.

(_) C₃H₈(g) + 2 O₂(g)

3 CO₂(g) + 4 H₂O(g)

(_) 2 C₂H₆(g) + 4 O₂(g)

4 CO₂(g) + 2 H₂O(g)

(o) 2 C₂H₆(g) + 7 O₂(g)

4 CO₂(g) + 6 H₂O(g)

(_) CH₄(g) + 2 O₂(g)

CO₂(g) + 2 H₂O(g)

Silber4 3.112e.EOCP.

Convert the following description of the reaction into a balanced equation.

Iron(II) chloride can be converted to iron(III) fluoride by treatment with chlorine trifluoride gas. Chlorine gas is also formed.

(_) FeCl₂(s) + ClF₃(g)

FeF₃(s) + 3 Cl (g)

(_) Fe₃Cl₂(s) + 4 ClF₃(g)

Fe₃F₃(s) + 3 Cl₂(g)

(o) 2 FeCl₂(s) + 2 ClF₃(g)

2 FeF₃(s) + 3 Cl₂(g)

(_) FeCl₂(s) + ClF₃(g)

FeF₃(s) + Cl₂(g)

Silber4 3.113.AP. ,

Isobutylene is a hydrocarbon used in the manufacture of synthetic rubber. When 0.847 g of isobutylene was analyzed by combustion (using an apparatus similar to that of Figure 3.5), the gain in mass of the CO₂ absorber was 2.657 g and that of the H₂O absorber was 1.089 g. What is the empirical formula of isobutylene? (Type your answer using format CH4 for CH₄.)
[CH2]

Figure 3.5

Silber4 3.113.EOCP.

Isobutylene is a hydrocarbon used in the manufacture of synthetic rubber. When 0.847 g of isobutylene was analyzed by combustion (using an apparatus similar to that of Figure 3.4 in the text), the gain in mass of the CO₂ absorber was 2.657 g and that of the H₂O absorber was 1.089 g. What is the empirical formula of isobutylene?

(_) C₄H₈

(_) C₄H₁₀

(o) CH₂

(_) CH

Silber4 3.114.AP.

One of the compounds used to increase the octane rating of gasoline is toluene (below). Suppose 19.9 mL toluene (d = 0.867 g/mL) is consumed when a sample of gasoline burns in air.

(a) How many grams of oxygen are needed for complete combustion of the toluene?

[53.9] g
(b) How many total moles of gaseous products form?

[2.06] mol
(c) How many molecules of water vapor form?

[4.51e+23] molecules

Silber4 3.114a.EOCP.

One of the compounds used to increase the octane rating of gasoline is toluene (below). Suppose 15.0 mL of toluene (d = 0.867 g/mL) is consumed when a sample of gasoline burns in air.

How many grams of oxygen are needed for complete combustion of the toluene?

(_) 5.21 g O₂

(_) 4.5 g O₂

(o) 40.6 g O₂

(_) 49.81 g O₂

Silber4 3.114b.EOCP.

One of the compounds used to increase the octane rating of gasoline is toluene (below). Suppose 15.0 mL of toluene (d = 0.867 g/mL) is consumed when a sample of gasoline burns in air.

How many total moles of gaseous products form?

(_) 11 mol gaseous products

(_) 0.141 mol gaseous products

(o) 1.55 mol gaseous products

(_) 0.987 mol gaseous products

Silber4 3.115.EOCP.

The smelting of ferric oxide to form elemental iron occurs at high temperatures in a blast furnace through a reaction sequence with carbon monoxide. In the first step, ferric oxide reacts with carbon monoxide to form Fe₃O₄. This substance reacts with more carbon monoxide to form iron(II) oxide, which reacts with still more carbon monoxide to form molten iron. Carbon dioxide is also produced in each step. Write an overall balanced equation for the iron-smelting process.

(_) 3 Fe₂O₃ + CO

2 Fe₃O₄ + CO₂

(_) 2 Fe₃O₄ + 2CO

6 FeO + 2 CO₂

(o) Fe₂O₃ + 3 CO

2 Fe + 3 CO₂

(_) 6 FeO + 6 CO

6 Fe + 9 CO₂

Silber4 3.116.AP.

During studies of the following reaction (i), a chemical engineer measured a less-than-expected yield of N₂ and discovered that the following side reaction (ii) occurs.

(i)	N₂O₄(l) + 2 N₂H₄(l) 3 N₂(g) + 4 H₂O(g)
(ii)	2 N₂O₄(l) + N₂H₄(l) 6 NO(g) + 2 H₂O(g)

In one experiment 13.3 g of NO formed when 101.7 g of each reactant was used. What is the highest percent yield of N₂ that can be expected?

[86.6]%

Silber4 3.116.EOCP.

During studies of the reaction shown below:

N₂O₄(l) + 2 N₂H₄(l)

3 N₂(g) + 4 H₂O(g)

a chemical engineer measured a less-than-expected yield of N₂ and discovered that the following side reaction occurs:

2 N₂O₄(l) + N₂H₄(l)

6 NO(g) + 2 H₂O(g)

In one experiment, 10.0 g of NO formed when 100.0 g of each reactant was used. What is the highest percent yield of N₂ that can be expected?

(_) 97.6% N₂

(_) 32.61% N₂

(o) 89.8% N₂

(_) 29.28% N₂

Silber4 3.117.EOCP.

A mathematical equation useful for dilution calculations is M_dil

V_dil = M_conc

V_conc. This equation works because the quantity of the solution remains the same.

(_) True

(o) False

Silber4 3.118.AP.

The following boxes represent a chemical reaction between AB₂ and B₂.

(a) Write a balanced equation for the reaction. (Type your answer using the format CO2 for CO₂. Use the lowest possible coefficients.)
[2]AB₂ + [1]B₂

[2] [AB3]
(b) What is the limiting reactant in this reaction?
[AB2]
(c) How many moles of product can be made from 2.8 mol B₂ and 5.6 mol AB₂?

[5.6] mol
(d) How many moles of excess reactant remain after the reaction in part (c)?

[0] mol

Silber4 3.118a.EOCP.

The boxes below represent a chemical reaction between AB₂ and B₂.

Give the balanced equation for the reaction.

(_) AB₂ + B₂

AB₃

(_) AB₂ + B₂

AB₃ + 2 B

(o) 2 AB₂ + B₂

2 AB₃

(_) 6 AB₂ + 5 B₂

6 AB₃ + 2 B₂

Silber4 3.118b.EOCP.

The boxes below represent a chemical reaction between AB₂ and B₂.

What is the limiting reactant in this reaction?

(_) AB₃

(_) B

(o) AB₂

(_) B₂

Silber4 3.118c.EOCP.

The boxes below represent a chemical reaction between AB₂ and B₂.

How many moles of AB₃ can be made from 3.0 mol of B₂ and 5.0 mol of AB₂?

(_) 3.0 mol AB₃

(_) 2.0 mol AB₃

(o) 5.0 mol AB₃

(_) 6.0 mol AB₃

Silber4 3.119.AP.

Calculate each of the following quantities.

(a) volume of 16.4 M sulfuric acid that must be added to water to prepare 2.00 L f a 0.329 M solution

[0.0401] L
(b) molarity of the solution obtained by diluting 81.5 mL of 0.250 M ammonium chloride to 0.250 L

[0.0815] M
(c) volume of water added to 0.150 L of 0.0284 M sodium hydroxide to obtain a 0.0100 M solution (assume the volumes are additive at these low concentrations)

[0.276] L
(d) mass of calcium nitrate in each milliliter of a solution prepared by diluting 52.6 mL of 0.772 M calcium nitrate to a final volume of 0.100 L

[0.0666] g

Silber4 3.119c.EOCP.

Calculate the volume of water added to 0.150 L of 0.0262 M sodium hydroxide to obtain a 0.0100 M solution (assume the volumes are additive at these low concentrations).

(_) 0.543 L water

(_) 0.336 L water

(o) 0.243 L water

(_) 0.393 L water

Silber4 3.119d.EOCP.

Calculate the mass of calcium nitrate in each milliliter of a solution prepared by diluting 64.0 mL of 0.745 M calcium nitrate to a final volume of 0.100 L

(_) 78.28 g Ca(NO₃)₂

(_) 1.164 g Ca(NO₃)₂

(o) 0.0783 g Ca(NO₃)₂

(_) 0.477 g Ca(NO₃)₂

Silber4 3.120.EOCP.

Agricultural biochemists use 6-benzylaminopurine (C₁₂H₁₁N₅) in trace amounts as a plant growth regulator. In a typical application, 150. mL of a solution contains 0.030 mg of the compound. What is the molarity of the solution?

(_) 4.5

10^-2 M C₁₂H₁₁N₅

(_) 8.9

10^-4 M C₁₂H₁₁N₅

(o) 8.9

10^-7 M C₁₂H₁₁N₅

(_) 2.0

10^-8 M C₁₂H₁₁N₅

Silber4 3.121.AP.

One of Germany's largest chemical manufacturers is building a new plant to produce 3.60

10⁸ lb vinyl acetate per year. This compound (below) is used to make some of the polymers in adhesives, paints, fabric coatings, floppy disks, plastic films, and so on. Assuming production goals are met, how many moles of vinyl acetate will the plant produce each month?

[1.58e+08] mol

Silber4 3.121.EOCP.

One of Germany's largest chemical manufacturers has built a plant to produce 3.74

10⁸ lb of vinyl acetate per year. This compound (below) is used to make some of the polymers in adhesives, paints, fabric coatings, floppy disks, plastic films, and so on.

Assuming production goals are met, how many moles of vinyl acetate will the plant produce each month?

(_) 3.630

10⁵ mol vinyl acetate each month

(_) 4.34

10⁶ mol vinyl acetate each month

(o) 1.64

10⁸ mol vinyl acetate each month

(_) 1.970

10⁹ mol vinyl acetate each month

Silber4 3.122a.EOCP.

Seawater is approximately 4.0% by mass dissolved ions. About 85% of the mass of the dissolved ions is from NaCl. Calculate the percent by mass of NaCl in seawater.

(_) 0.047% NaCl

(_) 21.2% NaCl

(o) 3.4% NaCl

(_) 0.034% NaCl

Silber4 3.122b.EOCP.

Seawater is approximately 4.0% by mass dissolved ions. About 85% of the mass of the dissolved ions is from NaCl. Calculate the percent by mass of Na⁺ ions in seawater.

(_) 0.078%

(_) 0.00086%

(o) 1.3%

(_) 0.034%

Silber4 3.122c.EOCP.

Seawater is approximately 4.0% by mass dissolved ions. About 85% of the mass of the dissolved ions is from NaCl. Calculate the percent by mass of Cl^- ions in seawater.

(_) 5.6%

(_) 0.00021%

(o) 2.1%

(_) 0.034%

Silber4 3.122d.EOCP.

Seawater is approximately 4.0% by mass dissolved ions. About 85% of the mass of the dissolved ions is from NaCl. Calculate the molarity of NaCl in seawater at 15°C. (d of seawater at 15°C = 1.025g/mL)

(_) 0.00060 M

(_) 0.0019 M

(o) 0.60 M

(_) 0.70 M

Silber4 3.124a.EOCP.

Box A represents one unit volume of solution A.

Which box represents one unit volume after adding enough solvent to solution A to triple its volume?

(_) Box B

(_) not enough information

(o) Box C

(_) Box D

Silber4 3.124b.EOCP.

Box A represents one unit volume of solution A.

Which box represents one unit volume after adding enough solvent to solution A to double its volume?

(_) Box C

(_) not enough information

(o) Box B

(_) Box D

Silber4 3.124c.EOCP.

Box A represents one unit volume of solution A.

Which box represents one unit volume after adding enough solvent to solution A to quadruple its volume?

(_) Box B

(_) not enough information

(o) Box D

(_) Box C

Silber4 3.125a.EOCP.

Choose the larger of the following quantities.

Number of entities: 0.4 mol of O₃ molecules or 0.4 mol of O atoms

(_) 0.4 mol of O₃ molecules

(_) not enough information to decide to decide

(o) both quantities are equal

(_) 0.4 mol of O atoms

Silber4 3.125b.EOCP.

Choose the larger of the following quantities.

mass: 0.4 mol of O₃ molecules or 0.4 mol of O atoms

(_) 0.4 mol of O atoms

(_) not enough information

(o) 0.4 mol of O₃ molecules

(_) both quantities are equal

Silber4 3.125c.EOCP.

Choose the larger of the following quantities.

number of moles: 4.0 g of N₂O₄ or 3.3 g of SO₂

(_) 4.0 g of N₂O₄

(_) not enough information to decide

(o) 3.3 g of SO₂

(_) both quantities are equal

Silber4 3.125d.EOCP.

Choose the larger of the following quantities.

mass: 0.6 mol of C₂H₄ or 0.6 mol of F₂

(_) 0.6 mol of C₂H₄

(_) not enough information to decide

(o) 0.6 mol of F₂

(_) both quantities are equal

Silber4 3.125e.EOCP.

Choose the larger of the following quantities.

total number of ions: 2.3 mol of sodium chlorate or 2.2 mol of magnesium chloride

(_) 2.3 mol of sodium chlorate

(_) not enough information

(o) 2.2 mol of magnesium chloride

(_) both quantities are equal

Silber4 3.125f.EOCP.

Choose the larger of the following quantities.

number of molecules: 1.0 g of H₂O or 1.0 g of H₂O₂

(_) 1.0 g of H₂O₂

(_) not enough information

(o) 1.0 g of H₂O

(_) both quantities are equal

Silber4 3.125g.EOCP.

Choose the larger of the following quantities.

number of Na⁺ ions: 0.500 L of 0.500 M NaBr or 0.0146 kg of NaCl

(_) 0.500 L of 0.500 M NaBr

(_) not enough information to decide

(o) both quantities are equal

(_) 0.0146 kg of NaCl

Silber4 3.125h.EOCP.

Choose the larger of the following quantities.

mass: 6.02

10²³ atoms of ²³⁵U or 6.02

10²³ atoms of ²³⁸U

(_) 6.02

10²³ atoms of ²³⁵U

(_) not enough information

(o) 6.02

10²³ atoms of ²³⁸U

(_) both quantities are equal

Silber4 3.126.EOCP.

Balance the equation for the reaction between solid tetraphosphorus trisulfide and oxygen gas to form solid tetraphosphorus decaoxide and gaseous sulfur dioxide.

(_) 2 P₃S₃(s) + 16 O₂(g)

2 P₃O₁₀(s) + 6 SO₂(g)

(_) P₃S₃(s) + 5 O₂(g)

P₃O₁₀(s) + 3 SO₂(g)

(o) P₄S₃(s) + 8 O₂(g)

P₄O₁₀(s) + 3 SO₂(g)

(_) P₄S₃(s) + 5 O₂(g)

P₄O₁₀(s) + 3 SO₂(g)

Silber4 3.127.AP.

Hydrogen gas has been suggested as a clean fuel because it produces only water vapor when it burns. If the reaction has a 98.8% yield, what mass of hydrogen forms 77.1 kg of water?

[8.73] kg

Silber4 3.127.EOCP.

Hydrogen gas has been suggested as a clean fuel because it produces only water vapor when it burns. If the reaction has a 98.8% yield, what mass of hydrogen forms 85.0 kg of water?

(_) 170. kg H₂

(_) 4.77 kg H₂

(o) 9.62 kg H₂

(_) 9.509 kg H₂

Silber4 3.128.EOCP.

Assuming that the volumes are additive, what is the concentration of KBr in a solution prepared by mixing 0.200 L of 0.053 M KBr with 0.550 L of 0.078 M KBr?

(_) 0.0405 M KBr

(_) 0.054 M KBr

(o) 0.071 M KBr

(_) 0.0320 M KBr

Silber4 3.129a.EOCP.

Solar winds composed of free protons, electrons, and

particles, bombard Earth constantly, knocking gas molecules out of the atmosphere. In this way, Earth loses 3.0 kg of matter per second. It is estimated that the atmosphere will be gone in about 50 billion years.

Use this estimate to calculate the mass (kg) of Earth's atmosphere.

(_) 1.5

10¹² kg

(_) 1.6

10³ kg

(o) 4.7

10¹⁸ kg

(_) 7.9

10⁷ kg

Silber4 3.129b.EOCP.

Solar winds composed of free protons, electrons, and

(_) 4.5

10²⁰ mol

(_) 2.5

10¹⁸ mol

(o) 2.5

10²⁰ mol

(_) 3.6

10¹⁹ mol

Silber4 3.130.AP.

Calculate each of the following quantities.

(a) moles of compound in 0.580 g ammonium bromide

[0.00592] mol
(b) number of potassium ions in 59.9 g potassium nitrate

[3.57e+23] ions
(c) mass in grams of 5.77 mol glycerol (C₃H₈O₃)

[531] g
(d) volume of 2.35 mol of glycerol (CHCl₃; d=1.48 g/mL)

[1.90e+02] mL
(e) number of sodium ions in 3.65 mol sodium carbonate

[4.40e+24] ions
(f) number of atoms in 10.0 µg of cadmium

[5.36e+15] atoms
(g) number of atoms in 0.0015 mol fluorine gas

[1.8e+21] atoms

Silber4 3.130b.EOCP.

Calculate the number of potassium ions in 68.5 g of potassium nitrate.

(_) 4.8

10²³ K⁺ions

(_) 4.12

10²³ K⁺ions

(o) 4.08

10²³ K⁺ions

(_) 4.2

10²⁷ K⁺ions

Silber4 3.130d.EOCP.

Calculate the volume of 2.55 mol of chloroform (CHCl₃; d = 1.48 g/mL).

(_) 8.1

10¹ mL CHCl₃

(_) 3.045

10² mL CHCl₃

(o) 2.06

10² mL CHCl₃

(_) 4.51

10² mL CHCl₃

Silber4 3.130e.EOCP.

Calculate the number of sodium ions in 2.11 mol of sodium carbonate.

(_) 6.4

10²³Na⁺ ions

(_) 1.27

10²⁴Na⁺ ions

(o) 2.54

10²⁴Na⁺ ions

(_) 1.20

10²⁴Na⁺ ions

Silber4 3.131.AP.

Elements X (green) and Y (purple) react according to the following equation.

X₂ + 3 Y₂ 2 XY₃

Which molecular scene represents the product of the reaction?
[ C ]

Silber4 3.131.EOCP.

Elements X (green) and Y (purple) react according to the following equation: X₂ + 3 Y₂

2 XY₃.

Which molecular scene represents the product of the reaction?

(_) Scene A

(_) Scene B

(o) Scene C

(_) Scene D

Silber4 3.132.EOCP.

Hydrocarbon mixtures are used as fuels. How many grams of CO₂(g) are produced by the combustion of 200. g of a mixture that is 25.0% CH₄ and 75.0% C₃H₈ by mass?

(o) 586 g CO₂

(_) 102 g CO₂

(_) 312 g CO₂

(_) 414 g CO₂

Silber4 3.134.AP. ,

Nitrogen (N), phosphorus (P), and potassium (K) are the main nutrients in fertilizers. According to an industry convention, the numbers on the label refer to the mass percents of N, P₂O₅, and K₂O, in that order. Calculate the N : P : K ratio of a 30 : 10 : 10 fertilizer in terms of moles of each element, and express it as x : y : 1.0.
[10] : [0.67] : 1.0

Silber4 3.134.EOCP.

Nitrogen (N), phosphorus (P), and potassium (K) are the main nutrients in plant fertilizers. According to an industry convention, the numbers on the label refer to the mass percents of N, P₂O₅, and K₂O, in that order. Calculate the N:P:K ratio of a 30:10:10 fertilizer in terms of moles of each element, and express it as x:y:1.0.

(o) 10 : 0.67 : 1.0

(_) 2.1 : 0.14 : 1.0

(_) 3.0 : 1.0 : 1.0

(_) 0.14 : 0.21 : 1.0

Silber4 3.135.EOCP.

A 0.652 g sample of a pure strontium halide reacts with excess sulfuric acid, and the solid strontium sulfate formed is separated, dried, and found to weigh 0.755 g. What is the formula of the original halide?

(o) SrCl₂

(_) SrBr₂

(_) SrF₂

(_) SrI₂

Silber4 3.136.EOCP.

Methane and ethane are the two simplest hydrocarbons. What is the mass % C in a mixture that is 40.0% methane and 60.0% ethane by mass?

(_) 17.9 mass % C

(o) 77.9 mass % C

(_) 30.0 mass % C

(_) 47.9 mass % C

Silber4 3.137.EOCP.

When carbon-containing compounds are burned in a limited amount of air, some CO(g) as well as CO₂(g) is produced. A gaseous product mixture is 35.0 mass % CO and 65.0 mass % CO₂. What is the mass % C in the mixture?

(_) 15.0 mass % C

(o) 32.7 mass % C

(_) 17.7 mass % C

(_) 2.7 mass % C

Silber4 3.138.EOCP.

Ferrocene, first synthesized in 1951, was the first organic iron compound with direct Fe-C bonds. An understanding of ferrocene's structure gave rise to new ideas about chemical bonding and led to the preparation of many useful compounds. In the combustion analysis of ferrocene, which contains only Fe, C, and H, a 0.9437 g sample produced 2.233 g of CO₂ and 0.457 g of H₂O. What is the empirical formula of ferrocene?

(_) CHFe

(o) C₁₀H₁₀Fe

(_) C₅H₁₀Fe

(_) CHFe₂

Silber4 3.139.AP.

Citric acid (below) is concentrated in citrus fruits and plays a central metabolic role in nearly every animal and plant cell.

(a) What are the molar mass and formula of citric acid?
molar mass
[192] g/mol
formula (Type your answer using the format C6H11O6 for C₆H₁₁O₆.)
[C6H8O7]
(b) How many moles of citric acid are in 2.35 qt of lemon juice (d = 1.09 g/mL) that is 5.78% citric acid by mass?

[0.729] mol

Silber4 3.139b.EOCP.

Citric acid (below) is concentrated in citrus fruits and plays a central metabolic role in nearly every animal and plant cell.

How many moles of citric acid are in 1.50 qt of lemon juice (d = 1.09 g/mL) that is 6.82% citric acid by mass?

(_) 105 mol citric acid

(o) 0.549 mol citric acid

(_) 0.05 mol citric acid

(_) 54.9 mol citric acid

Silber4 3.140a.EOCP.

Various nitrogen oxides, as well as oxides of sulfur, contribute to acidic rainfall through complex reaction sequences. Atmospheric nitrogen and oxygen combine to form nitrogen monoxide gas, which reacts with more oxygen to form nitrogen dioxide gas. In contact with water vapor, nitrogen dioxide forms aqueous nitric acid and more nitrogen monoxide.

Give the overall balanced equation that does not include nitrogen monoxide and nitrogen dioxide.

(_) 4 N₂(g) + O₂(g) + 4 H₂O(l)

8 HNO₃(aq) + NO₃(g)

(o) 2 N₂(g) + 5 O₂(g) + 2 H₂O(l)

4 HNO₃(aq)

(_) N₂(g) + 3 O₂(g)

2 HNO₃(aq) + H₂O(l)

(_) 2 N(g) + 3 O₂(g) + H₂O(l)

2 HNO₃(aq)

Silber4 3.140b.EOCP.

Various nitrogen oxides, as well as oxides of sulfur, contribute to acidic rainfall through complex reaction sequences. Atmospheric nitrogen and oxygen combine to form nitrogen monoxide gas, which reacts with more oxygen to form nitrogen dioxide gas. In contact with water vapor, nitrogen dioxide forms aqueous nitric acid and more nitrogen monoxide.

How many metric tons (t) of nitric acid form when 1.25

10³ t of atmospheric nitrogen is consumed (1 t = 1000 kg)?

(_) 5.62

10¹⁰ t HNO₃

(_) 2.811

10³ t HNO₃

(_) 5.62

10^-4 t HNO₃

(o) 5.62

10³ t HNO₃

Silber4 3.141a.EOCP.

Alum [KAl(SO₄)₂ · xH₂O] is used in food preparation, dye fixation and water purification. A 0.5404 g sample of alum is heated to drive off the waters of hydration. The resulting KAl(SO₄)₂ weighs 0.2941 g. The value of x in the formula of alum is:

(_) 17

(_) 80

(_) 7

(o) 12

Silber4 3.141b.EOCP.

Alum [KAl(SO₄)₂ · 12H₂O] is used in food preparation, dye fixation and water purification. To prepare alum, aluminum is reacted with potassium hydroxide and the product with sulfuric acid. Upon cooling, alum crystallizes from the solution. When 0.7500 g of aluminum is used, 8.500 g of alum forms. The percent yield of this reaction is:

(_) 0.5485%

(_) 84.38%

(_) 13.19%

(o) 64.44%

Silber4 3.142.AP. ,

When 1.5173 of an organic iron compound containing Fe, C, H, and O was burned in O₂, 2.838 g of CO₂ and 0.8122 g of H₂O were produced. In a separate experiment to determine the mass % of iron, 0.3355 g of the compound yielded 0.0758 g of Fe₂O₃. What is the empirical formula of the compound? (Type your answer using the format CH4 for CH₄.)
[C15H21O6Fe]

Silber4 3.142.EOCP.

When 1.5173 g of an organic iron compound containing Fe, C, H, and O was burned in O₂, 2.838 g of CO₂ and 0.8122 g of H₂O were produced. In a separate experiment to determine the mass % of iron, 0.3355 g of the compound yielded 0.0758 g of Fe₂O₃. What is the empirical formula of the compound?

(_) C₁₀HO₃Fe₅

(_) C₅H₇O₂Fe

(_) CHOFe

(o) C₁₅H₂₁O₆Fe

Silber4 3.143a.EOCP.

Fluorine is so reactive that it forms compounds with materials inert to other treatments. When 0.327 g of platinum is heated in fluorine, 0.519 g of a dark red, volatile solid forms. The empirical formula of this compound is:

(_) Pt₂F₆

(_) Pt₆F₂

(_) PtF

(o) PtF₆

Silber4 3.143b.EOCP.

Fluorine is so reactive that it forms compounds with materials inert to other treatments. When 0.265 g of the compound PtF₆ reacts with excess xenon gas, 0.378 g of an orange-yellow solid forms. What is the empirical formula of this compound, the first noble gas compound formed?

(_) Xe₂PtF

(_) XePtF₁₂

(_) XePtF

(o) XePtF₆

Silber4 3.143b.EOCP.

Fluorides of the relatively unreactive noble gas xenon can be formed by direct reaction of the elements at high pressure and temperature. Depending on the temperature and the reactant amounts, the product mixture may include XeF₂, XeF₄, and XeF₆. Under conditions that produce only XeF₄ and XeF₆, 1.85

10^-4 mol of Xe reacted with 5.00

10^-4 mol of F₂, and 9.00

10^-6 mol of Xe was found to be in excess.

What is the mass percent of XeF₄ in the product?

(_) 2.46% XeF₄

(_) 84.8% XeF₄

(_) 58% XeF₄

(o) 14% XeF₄

Silber4 3.143c.EOCP.

10^-4 mol of Xe reacted with 5.00

10^-4 mol of F₂, and 9.00

10^-6 mol of Xe was found to be in excess.

What is the mass percent of XeF₆ in the product?

(_) 97.5% XeF₆

(_) 42% XeF₆

(_) 15.2% XeF₆

(o) 86.2% XeF₆

Silber4 3.144.AP.

Hemoglobin is 6.0% heme (C₃₄H₃₂FeN₄O₄) by mass. To remove heme, hemoglobin is treated with acetic acid and NaCl to form hemin (C₃₄H₃₂N₄O₄FeCl). At a crime scene, a blood sample contains 0.52 g of hemoglobin.

(a) How many grams of heme are in the sample?

[0.031] g
(b) How many moles of heme?

[5.1e-05] mol
(c) How many grams of Fe?

[0.0028] g
(d) How many grams of hemin could be formed for a forensic chemist to measure?

[0.033] g

Silber4 3.144a.EOCP.

Hemoglobin is 6.0% heme (C₃₄H₃₂FeN₄O₄) by mass. To remove the heme, hemoglobin is treated with acetic acid and NaCl to form hemin (C₃₄H₃₂N₄O₄FeCl). At a crime scene, a blood sample contains 0.45 g of hemoglobin.

How many grams of heme are in the sample?

(_) 0.0027 g heme

(_) 0.00027 g heme

(_) 0.27 g heme

(o) 0.027 g heme

Silber4 3.144b.EOCP.

(_) 4.4

10^-6 mol heme

(_) 4.4

10^-7 mol heme

(_) 4.4

10^-4 mol heme

(o) 4.4

10^-5 mol heme

Silber4 3.144c.EOCP.

(_) 2.4

10^-4 g Fe

(_) 2.4

10^-6 g Fe

(_) 2.4

10^-5 g Fe

(o) 2.4

10^-3 g Fe

Silber4 3.144c.EOCP.

(_) 2.9

10^-5 g hemin

(_) 2.9

10^-3 g hemin

(_) 2.9

10^-4 g hemin

(o) 2.9

10^-2 g hemin

Silber4 3.145a.EOCP.

Manganese is a key component of extremely hard steel. The element occurs naturally in many oxides. A 542.3 g sample of a manganese oxide mixture has an Mn:O molar ratio of 1.00:1.42 and consists of braunite (Mn₂O₃) and manganosite (MnO).

What is the mass percent of braunite in the ore?

(_) 5.31% braunite

(_) 21.3% braunite

(_) 14.0% braunite

(o) 85.4% braunite

Silber4 3.145b.EOCP.

(_) 78.7% manganosite

(_) 86.0% manganosite

(_) 94.7% manganosite

(o) 14.6% manganosite

Silber4 3.145c.EOCP.

(_) 4.00

(_) 17.8

(_) 8.01

(o) 5.25

Silber4 3.146a.EOCP.

Sulfur dioxide gas can be produced by roasting iron pyrite (iron disulfide, FeS₂) in oxygen, which yields the gas and solid iron(III) oxide. What mass of iron pyrite is used in the formation of 1.00 kg of sulfur dioxide?

(_) 3750 g

(_) 7.80 g

(_) 870 g

(o) 936 g

Silber4 3.146b.EOCP.

Sulfur dioxide gas can be produced by roasting iron pyrite (iron disulfide, FeS₂) in oxygen, which yields the gas and solid iron(III) oxide. What mass of oxygen is used in the formation of 1.00 kg of sulfur dioxide?

(_) 363 g

(_) 21.5 g

(_) 499 g

(o) 687 g

Silber4 3.146c.EOCP.

Sulfur dioxide gas can be produced by roasting iron pyrite (iron disulfide, FeS₂) in oxygen, which yields the gas and solid iron(III) oxide. What mass of iron(III) oxide is produced in the formation of 1.00 kg of sulfur dioxide?

(_) 2490 g

(_) 62.4 g

(_) 3.90 g

(o) 623 g

Silber4 3.147a.EOCP.

The human body excretes nitrogen in the form of urea, NH₂CONH₂. The key biochemical step in urea formation is the reaction of water with arginine to produce urea and ornithine:

What is the mass percent of nitrogen in urea?

(_) 21.43 mass % N

(_) 2.1 mass % N

(_) 23.3 mass % N

(o) 46.65 mass % N

Silber4 3.147b.EOCP.

The human body excretes nitrogen in the form of urea, NH₂CONH₂. The key biochemical step in urea formation is the reaction of water with arginine to produce urea and ornithine:

What is the mass percent of nitrogen in arginine?

(_) 16.1 mass % N

(_) 31.09 mass % N

(_) 8.04 mass % N

(o) 32.17 mass % N

Silber4 3.147c.EOCP.

The human body excretes nitrogen in the form of urea, NH₂CONH₂. The key biochemical step in urea formation is the reaction of water with arginine to produce urea and ornithine:

What is the mass percent of nitrogen in ornithine?

(_) 4.71 mass % N

(_) 47.17 mass % N

(_) 10.6 mass % N

(o) 21.20 mass % N

Silber4 3.147d.EOCP.

The human body excretes nitrogen in the form of urea, NH₂CONH₂. The key biochemical step in urea formation is the reaction of water with arginine to produce urea and ornithine:

How many grams of nitrogen can be excreted as urea when 143.2 g of ornithine is produced?

(_) 111 g N

(_) 50.54 g N

(_) 65.1 g N

(o) 30.36 g N

Silber4 3.148a.EOCP.

Aspirin (acetylsalicylic acid, C₉H₈O₄) can be made by reacting salicylic acid (C₇H₆O₃) with acetic anhydride [(CH₃CO)₂O]:

C₇H₆O₃(s) + (CH₃CO)₂O(l)

C₉H₈O₄(s) + CH₃COOH(l)

In one reaction, 3.027 g of salicylic acid and 6.00 mL of acetic anhydride react to form 3.261 g of aspirin. Which is the limiting reactant? (d of acetic anhydride = 1.080 g/mL.)

(_) C₉H₈O₄

(_) CH₃COOH

(_) (CH₃CO)₂O

(o) C₇H₆O₃

Silber4 3.148b.EOCP.

Aspirin (acetylsalicylic acid, C₉H₈O₄) can be made by reacting salicylic acid (C₇H₆O₃) with acetic anhydride [(CH₃CO)₂O]:

C₇H₆O₃(s) + (CH₃CO)₂O(l)

C₉H₈O₄(s) + CH₃COOH(l)

In one reaction, 3.027 g of salicylic acid and 6.00 mL of acetic anhydride react to form 3.261 g of aspirin. What is the percent yield of aspirin of this reaction?

(_) 28.51%

(_) 76.67%

(_) 26.46%

(o) 82.60%

Silber4 3.148c.EOCP.

Aspirin (acetylsalicylic acid, C₉H₈O₄) can be made by reacting salicylic acid (C₇H₆O₃) with acetic anhydride [(CH₃CO)₂O]:

C₇H₆O₃(s) + (CH₃CO)₂O(l)

C₉H₈O₄(s) + CH₃COOH(l)

What is the percent atom economy of this reaction?

(_) 60.05%

(_) 25.00%

(_) 42.50%

(o) 75.00%

Silber4 3.149.EOCP.

The rocket fuel hydrazine (N₂H₄) is manufactured by the Raschig process, a three-step reaction with the following overall equation:

NaOCl(aq) + 2 NH₃(aq)

N₂H₄(aq) + NaCl(aq) + H₂O(l)

What is the percent atom economy of this process?

(_) 53.86%

(_) 16.60%

(_) 18.59%

(o) 29.54%

Silber4 3.150.EOCP.

Lead(II) chromate (PbCrO₄) is used as a yellow pigment to designate traffic lanes, but has been banned from house paint because of the potential for lead poisoning. The compound is produced from chromite (FeCr₂O₄), an ore of chromium, by the following reaction.

4 FeCr₂O₄(s) + 8 K₂CO₃(aq) + 7 O₂(g)

2 Fe₂O₃(s) + 8 K₂CrO₄(aq) + 8 CO₂(g)

Lead(II) ion then replaces K⁺ ions in a subsequent step. If a yellow paint is 0.511% PbCrO₄ by mass, how many grams of chromite are needed per kilogram of paint?

(_) 3.5 g FeCr₂O₄

(_) 1.8 g FeCr₂O₄

(_) 7.9 g FeCr₂O₄

(o) 2 g FeCr₂O₄

Silber4 3.151a.EOCP.

Ethanol (CH₃CH₂OH), the intoxicant in alcoholic beverages, is also used as a precursor of many other organic compounds. In concentrated sulfuric acid, ethanol forms diethyl ether:

2 CH₃CH₂OH(l)

CH₃CH₂OCH₂CH₃(l) + H₂O(g)

In a side reaction, some ethanol forms ethylene:

CH₃CH₂OH(l)

CH₂=CH₂(g) + H₂O(g)

If 50.0 g of ethanol yields 33.9 g of diethyl ether, what is the percent yield of diethyl ether?

(_) 42.16% diethyl ether

(_) 67.8% diethyl ether

(_) 54.26% diethyl ether

(o) 84.3% diethyl ether

Silber4 3.151b.EOCP.

Ethanol (CH₃CH₂OH), the intoxicant in alcoholic beverages, is also used as a precursor of many other organic compounds. In concentrated sulfuric acid, ethanol forms diethyl ether:

2 CH₃CH₂OH(l)

CH₃CH₂OCH₂CH₃(l) + H₂O(g)

In a side reaction, some ethanol forms ethylene:

CH₃CH₂OH(l)

CH₂=CH₂(g) + H₂O(g)

50.0 g of ethanol yields 33.9 g of diethyl ether. During the process, 50.0% of the ethanol that did not produce diethyl ether reacts by the side reaction. What mass of ethylene is produced?

(_) 15.2 g C₂H₄

(_) 30.4 g C₂H₄

(_) 4.90 g C₂H₄

(o) 2.39 g C₂H₄

Silber4 3.152a.EOCP.

When powdered zinc is heated with sulfur, a violent reaction occurs, and zinc sulfide forms according to the unbalanced reaction:

Zn(s) + S₈(s)

ZnS(s)

Some of the reactants also combine with oxygen in air to form zinc oxide and sulfur dioxide. When 85.2 g of Zn reacts with 52.4 g of S₈, 105.4 g of ZnS forms.

What is the percent yield of ZnS?

(_) 76.74% ZnS

(_) 12.7% ZnS

(_) 19.9% ZnS

(o) 83.0% ZnS

Silber4 3.152b.EOCP.

When powdered zinc is heated with sulfur, a violent reaction occurs, and zinc sulfide forms according to the unbalanced reaction:

Zn(s) + S₈(s)

ZnS(s)

Some of the reactants also combine with oxygen in air to form zinc oxide and sulfur dioxide. When 85.2 g of Zn reacts with 52.4 g of S₈, 105.4 g of ZnS forms.

If all the remaining reactants combine with oxygen, how many grams of zinc oxide form?

(_) 24.6 g ZnO

(_) 92.37 g ZnO

(_) 84.75 g ZnO

(o) 18.0 g ZnO

Silber4 3.152c.EOCP.

When powdered zinc is heated with sulfur, a violent reaction occurs, and zinc sulfide forms according to the unbalanced reaction:

Zn(s) + S₈(s)

ZnS(s)

(_) 40.84 g SO₂

(_) 94.0 g SO₂

(_) 88.0 g SO₂

(o) 35.6 g SO₂

Silber4 3.153.EOCP.

Cocaine (C₁₇H₂₁O₄N) is a natural substance found in coca leaves, which have been used for centuries as a local anesthetic and stimulant. Illegal cocaine arrives in the United States either as the pure compound or as the hydrochloride salt (C₁₇H₂₁O₄NHCl). At 25°C, the salt is very soluble in water (2.50 kg/L), but cocaine is much less so (1.70 g/L).

What is the maximum amount (in g) of the salt that can dissolve in 50.0 mL of water?

(_) 12.5 g salt

(_) 1250 g salt

(_) 1.25 g salt

(o) 125 g salt

Silber4 3.154a.EOCP.

High temperature superconducting oxides hold great promise in the utility, transportation, and computer industries. One superconductor is La_2-xSr_xCuO₄.

Calculate the molar mass of this oxide when x = 0.

(_) 127.55 amu

(_) 266.45 amu

(_) 492.97 amu

(o) 405.35 amu

Silber4 3.154b.EOCP.

(_) 306.07 amu

(_) 441.69 amu

(_) 492.97 amu

(o) 354.07 amu

Silber4 3.154c.EOCP.

(_) 405.35 amu

(_) 354.07 amu

(_) 492.97 amu

(o) 396.99 amu

Silber4 3.154d.EOCP.

A common superconducting oxide is made by heating a mixture of barium carbonate, copper(II) oxide, and yttrium(III) oxide, followed by further heating in O₂:

4 BaCO₃(s) + 6 CuO(s) + Y₂O₃(s)

2 YBa₂Cu₃O_6.5(s) + 4 CO₂(g)
2 YBa₂Cu₃O_6.5(s) + 1/2 O₂(g)

2 YBa₂Cu₃O₇(s)

When equal masses of the three reactants are heated, which reactant is limiting?

(_) Y₂O₃

(_) CuO

(_) YBa₂Cu₃O₇

(o) BaCO₃

Silber4 3.155.EOCP.

The zirconium oxalate K₂Zr(C₂O₄)₃(H₂C₂O₄) · H₂O, was synthesized by mixing 1.60 g of ZrOCl₂ · 8 H₂O with 5.20 g of H₂C₂O₄ · 2 H₂O and an excess of aqueous KOH. After 2 months, 1.20 g of crystalline product was obtained, as well as aqueous KCl and water. The percent yield of this reaction is:

(_) 5.37%

(_) 21.5%

(_) 14.5%

(o) 44.6%

Silber4 3.FP.01.

FOLLOW-UP PROBLEM 3.1

Calculating the Mass and Number of Atoms in a Given Number of Moles of an Element

(a) Graphite is the crystalline form of carbon used in lead pencils. How many moles of carbon are there in 335 mg of graphite?

[0.0279] mol

(b) Manganese (Mn) is a transition element essential for the growth of bones. What is the mass in grams of 1.29

10²¹ Mn atoms, the number found in 4.00 kg of bone.

[0.118] g

HINTS

Getting Started

I'm Stuck

Silber4 3.TB.001.

Calcium fluoride, CaF₂, is a source of fluorine and is used to fluoridate drinking water. Calculate its molar mass.

(_) 99.15 g/mol

(o) 78.07 g/mol

(_) 118.15 g/mol

(_) 50.01 g/mol

(_) 59.08 g/mol

Silber4 3.TB.002.

Calculate the molar mass of tetraphosphorus decaoxide, P₄O₁₀, a corrosive substance which can be used as a drying agent.

(_) 190.97 g/mol

(o) 283.89 g/mol

(_) 469.73 g/mol

(_) 94.97 g/mol

(_) 139.88 g/mol

Silber4 3.TB.005.

Aluminum sulfate, Al₂(SO₄)₃, is used in tanning leather, purifying water, and manufacture of antiperspirants. Calculate its molar mass.

(_) 315.15 g/mol

(o) 342.15 g/mol

(_) 450.06 g/mol

(_) 74.98 g/mol

(_) 278.02 g/mol

Silber4 3.TB.006.

Which of the following chemical equations is NOT balanced?

(_) H₃PO₄(aq) + Al(OH)₃(s)

3 H₂O(l) + AlPO₄(s)

(o) 3 H₂SO₄(aq) + 2 Al(OH)₃(s)

3 H₂O(l) + Al₂(SO₄)₃(aq)

(_) 2 NaOH(aq) + H₂SO₄(aq)

Na₂SO₄(aq) + 2 H₂O(l)

(_) 2 C₆H₁₄O₄(s) + 15 O₂(g)

14 H₂O(g) + 12 CO₂(g)

Silber4 3.TB.007.

Magnesium fluoride is used in the ceramics and glass industry. What is the mass of 1.72 mol of magnesium fluoride?

(_) 62.3 g

(o) 107 g

(_) 43.3 g

(_) 92.9 g

(_) 74.5 g

Silber4 3.TB.008.

Sodium bromate is used in a mixture which dissolves gold from its ores. Calculate the mass in grams of 4.68 mol of sodium bromate.

(_) 383 g

(o) 706 g

(_) 482 g

(_) 0.0310 g

(_) 32.2 g

Silber4 3.TB.011.

Phosphorus pentachloride, PCl₅, a white solid that has a pungent, unpleasant odor, is used as a catalyst for certain organic reactions. Calculate the number of moles in 38.7 g of PCl₅.

(_) 3.55 mol

(o) 0.186 mol

(_) 5.38 mol

(_) 0.282 mol

(_) 0.583 mol

Silber4 3.TB.012.

Aluminum oxide, Al₂O₃, is used as a filler for paints and varnishes as well as in the manufacture of electrical insulators. Calculate the number of moles in 47.51 g of Al₂O₃.

(_) 2.146 mol

(o) 0.4660 mol

(_) 2.377 mol

(_) 0.4207 mol

(_) 1.105 mol

Silber4 3.TB.013.

Calculate the number of oxygen atoms in 29.34 g of sodium sulfate, Na₂SO₄.

(_) 2.409

10²⁴ O atoms

(o) 4.976

10²³ O atoms

(_) 1.244

10²³ O atoms

(_) 1.166

10²⁵ O atoms

(_) 2.915

10²⁴ O atoms

Silber4 3.TB.014.

Potassium dichromate, K₂Cr₂O₇, is used in tanning leather, decorating porcelain and water proofing fabrics. Calculate the number of chromium atoms in 78.82 g of K₂Cr₂O₇.

(_) 2.248

10²⁴ Cr atoms

(o) 3.227

10²³ Cr atoms

(_) 9.490

10²⁵ Cr atoms

(_) 1.613

10²³ Cr atoms

(_) 1.124

10²⁴ Cr atoms

Silber4 3.TB.015.

Sulfur trioxide can react with atmospheric water vapor to form sulfuric acid that falls as acid rain. Calculate the mass in grams of 3.65

10²⁰ molecules of SO₃.

(_) 2.91

10^-2 g

(o) 4.85

10^-2 g

(_) 6.06

10^-4 g

(_) 1650 g

(_) 20.6 g

Silber4 3.TB.017.

What is the number of hydrogen atoms in 0.050 mol of C₃H₈O₃?

(_) 1.2

10²³ H atoms

(o) 2.4

10²³ H atoms

(_) 3.0

10²² H atoms

(_) none of these

(_) 4.8

10²³ H atoms

Silber4 3.TB.018.

Copper(II) sulfate pentahydrate, CuSO₄ · 5 H₂O, is used as a fungicide and algicide. Calculate the mass of oxygen in 1.000 mol of CuSO₄ · 5 H₂O.

(_) 96.00 g

(o) 144.0 g

(_) 249.7 g

(_) 64.00 g

(_) 80.00 g

Silber4 3.TB.019.

Lead (II) nitrate is a poisonous substance which has been used in the manufacture of special explosives and as a sensitizer in photography. Calculate the mass of lead in 139 g of Pb(NO₃)₂.

(_) 90.8 g

(o) 87.0 g

(_) 107 g

(_) 62.6 g

(_) 83.4 g

Silber4 3.TB.020.

Household sugar, sucrose, has the molecular formula C₁₂H₂₂O₁₁. What is the % of carbon in sucrose, by mass?

(_) 33.3%

(o) 42.1%

(_) 26.7%

(_) 52.8%

(_) 41.4%

Silber4 3.TB.021.

Gadolinium oxide, a colorless powder which absorbs carbon dioxide from the air, contains 86.76 mass % Gd. Determine its empirical formula.

(_) Gd₃O₄

(o) Gd₂O₃

(_) Gd₃O₂

(_) GdO

(_) Gd₄O₃

Silber4 3.TB.022.

Hydroxylamine nitrate contains 29.17 mass % N, 4.20 mass % H, and 66.63 mass % O. Determine its empirical formula.

(_) HN₆O₁₆

(o) H₂NO₂

(_) HNO

(_) H₂NO₃

(_) HN₁₆O₇

Silber4 3.TB.023.

Hydroxylamine nitrate contains 29.17 mass % N, 4.20 mass % H, and 66.63 mass O. If its molar mass is between 94 and 98 g/mol, what is its molecular formula?

(_) N₃H₃O₃

(o) N₂H₄O₄

(_) NH₂O₅

(_) N₂H₂O₄

(_) N₄H₈O₂

Silber4 3.TB.024.

A compound of bromine and fluorine is used to make UF₆, which is an important chemical in processing and reprocessing of nuclear fuel. The compound contains 58.37 mass percent bromine. Determine its empirical formula.

(_) BrF₂

(o) BrF₃

(_) BrF

(_) Br₃F

(_) Br₂F₃

Silber4 3.TB.025.

A compound containing chromium and silicon contains 73.52 mass percent chromium. Determine its empirical formula.

(_) Cr₃Si

(_) Cr₂Si₃

(_) CrSi₃

(_) Cr₂S

(o) Cr₃Si₂

Silber4 3.TB.026.

Alkanes are compounds of carbon and hydrogen with the general formula C_nH_{2n + 2}. An alkane component of gasoline has a molar mass of between 125 and 130 g/mol. What is the value of n for this alkane?

(_) 13

(_) 10

(_) 4

(_) 14

(o) 9

Silber4 3.TB.027.

Terephthalic acid, used in the production of polyester fibers and films, is composed of carbon, hydrogen, and oxygen. When 0.6943 g of terephthalic acid was subjected to combustion analysis it produced 1.471 g CO₂ and 0.226 g H₂O. What is its empirical formula?

(_) C₅H₁₂O₄

(_) C₃H₄O₂

(_) C₂H₃O₄

(_) C₂H₂O

(o) C₄H₃O₂

Silber4 3.TB.028.

(_) C₇H₁₂O₄

(_) C₆H₈O₅

(_) C₄H₆O₇

(_) C₄H₃O₂

(o) C₈H₆O₄

Silber4 3.TB.029.

Hydroxylamine hydrochloride is a powerful reducing agent which is used as a polymerization catalyst. It contains 5.80 mass % H, 20.16 mass % N, 23.02 mass % O, and 51.02 mass % Cl. What is its empirical formula?

(_) HN₃O₄Cl₉

(_) H₂N₂O₂Cl

(_) H₂N₇O₈Cl₁₈

(_) H₄NOCl₂

(o) H₄NOCl

Silber4 3.TB.030.

In the combustion analysis of 0.1127 g of glucose (C₆H₁₂O₆), what mass, in grams, of CO₂ would be produced?

(_) 0.4132 g

(_) 0.0825 g

(_) 0.0451 g

(_) 1.466 g

(o) 0.1652 g

Silber4 3.TB.031.

Balance the following equation: B₂O₃(s) + HF(l)

BF₃(g) + H₂O(l).

(_) B₂O₃(s) + 3 HF(l)

2 BF₃(g) + 3 H₂O(l)

(_) B₂O₃(s) + 2 HF(l)

2 BF₃(g) + H₂O(l)

(_) B₂O₃(s) + H₆F₆(l)

B₂F₆(g) + H₆O₃(l)

(_) B₂O₃(s) + 6 HF(l)

2 BF₃(g) + 6 H₂O(l)

(o) B₂O₃(s) + 6 HF(l)

2 BF₃(g) + 3 H₂O(l)

Silber4 3.TB.032.

Balance the following equation: UO₂(s) + HF(l)

UF₄(s) + H₂O(l).

(_) UO₂(s) + 4 HF(l)

UF₄(s) + 4 H₂O(l)

(_) UO₂ (s) + H₄F₄(l)

UF₄ (s) + H₄O₂(l)

(_) UO₂(s) + 2 HF(l)

UF₄(s) + H₂O(l)

(_) UO₂(s) + 8 HF(l)

2 UF₄(s) + 4 H₂O(l)

(o) UO₂(s) + 4 HF(l)

UF₄(s) + 2 H₂O(l)

Silber4 3.TB.033.

Balance the following equation for the combustion of benzene: C₆H₆(l) + O₂(g)

H₂O(g) + CO₂(g).

(_) C₆H₆(l) + 15 O₂(g)

3 H₂O(g) + 6 CO₂(g)

(_) C₆H₆(l) + 9 O₂(g)

6 H₂O(g) + 6 CO₂(g)

(_) C₆H₆(l) + 9 O₂(g)

3 H₂O(g) + 6 CO₂(g)

(_) 2 C₆H₆(l) + 9 O₂(g)

6 H₂O(g) + 12 CO₂(g)

(o) 2 C₆H₆(l) + 15 O₂(g)

6 H₂O(g) + 12 CO₂(g)

Silber4 3.TB.034.

Balance the following equation: C₈H₁₈O₃(l) + O₂(g)

H₂O(g) + CO₂(g).

(_) C₈H₁₈O₃(l) + 13 O₂(g)

18 H₂O(g) + 8 CO₂(g)

(_) 2 C₈H₁₈O₃(l) + 22 O₂(g)

9 H₂O(g) + 16 CO₂(g)

(_) C₈H₁₈O₃(l) + 8 O₂(g)

9 H₂O(g) + 8 CO₂(g)

(_) 2 C₈H₁₈O₃(l) + 17 O₂(g)

18 H₂O(g) + 16 CO₂(g)

(o) C₈H₁₈O₃(l) + 11 O₂(g)

9 H₂O(g) + 8 CO₂(g)

Silber4 3.TB.035.

Balance the following equation: Ca₃(PO₄)₂(s) + SiO₂(s) + C(s)

CaSiO₃(s) + CO(g) + P₄(s).

(_) Ca₃(PO₄)₂(s) + 3 SiO₂(s) + 8 C(s)

3 CaSiO₃(s) + 8 CO(g) + 2 P₄(s)

(_) Ca₃(PO₄)₂(s) + 3 SiO₂(s) + 14 C(s)

3 CaSiO₃(s) + 14 CO(g) + P₄(s)

(_) Ca₃(PO₄)₂(s) + 3 SiO₂(s) + 8 C(s)

3 CaSiO₃(s) + 8 CO(g) + P₄(s)

(_) 2 Ca₃(PO₄)₂(s) + 6 SiO₂(s) + 10 C(s)

6 CaSiO₃(s) + 10 CO(g) + 4 P₄(s)

(o) 2 Ca₃(PO₄)₂(s) + 6 SiO₂(s) + 10 C(s)

6 CaSiO₃(s) + 10 CO(g) + P₄(s)

Silber4 3.TB.036.

Sulfur dioxide reacts with chlorine to produce thionyl chloride (used as a drying agent for inorganic halides) and dichlorine oxide (used as a bleach for wood, pulp and textiles). SO₂(g) + 2 Cl₂(g)

SOCl₂(g) + Cl₂O(g) If 0.400 mol of Cl₂ reacts with excess SO₂, how many moles of Cl₂O are formed?

(_) 0.100 mol

(_) 0.400 mol

(_) 0.800 mol

(_) 0.0500 mol

(o) 0.200 mol

Silber4 3.TB.037.

Aluminum will react with bromine to form aluminum bromide (used as an acid catalyst in organic synthesis).

Al(s) + Br₂(l) Al₂Br₆(s) [unbalanced]

How many moles of Al are needed to form 2.43 mol of Al₂Br₆?

(_) 1.62 mol

(_) 2.43 mol

(_) 7.29 mol

(_) 1.22 mol

(o) 4.86 mol

Silber4 3.TB.038.

Ammonia will react with fluorine to produce dinitrogen tetrafluoride and hydrogen fluoride (used in production of aluminum, in uranium processing, and in frosting of light bulbs).

2 NH₃(g) + 5 F₂(g) N₂F₄(g) + 6 HF(g)

How many moles of NH₃ are needed to react completely with 13.6 mol of F₂?

(_) 6.80 mol

(_) 27.2 mol

(_) 34.0 mol

(_) 2.27 mol

(o) 5.44 mol

Silber4 3.TB.039.

Ammonia, an important source of fixed nitrogen that can be metabolized by plants, is produced using the Haber process in which nitrogen and hydrogen combine.

N₂(g) + 3 H₂(g) 2 NH₃(g)

How many grams of nitrogen are needed to produce 325 grams of ammonia?

(_) 178 g

(_) 535 g

(_) 1070 g

(_) 108 g

(o) 267 g

Silber4 3.TB.040.

How many grams of sodium fluoride (used in water fluoridation and manufacture of insecticides) are needed to form 485 g of sulfur tetrafluoride?

3 SCl₂(l) + 4 NaF(s) SF₄(g) + S₂Cl₂(l) + 4 NaCl(s)

(_) 205 g

(_) 1510 g

(_) 1940 g

(_) 51.3 g

(o) 754 g

Silber4 3.TB.041.

How many grams of oxygen are needed to react completely with 200.0 g of ammonia, NH₃?

4 NH₃(g) + 5 O₂(g) 4 NO(g) + 6 H₂O(g)

(_) 3.406 g

(_) 250.0 g

(_) 300.6 g

(_) 2.180 g

(o) 469.7 g

Silber4 3.TB.042.

Phosphine, an extremely poisonous and highly reactive gas, will react with oxygen to form tetraphosphorus decaoxide and water.

PH₃(g) + O₂(g) P₄O₁₀(s) + H₂O(g) [unbalanced]

Calculate the mass of P4O₁₀(s) formed when 225 g of PH₃ reacts with excess oxygen.

(_) 900. g

(_) 940. g

(_) 1880 g

(_) 56.3 g

(o) 470 g

Silber4 3.TB.043.

Potassium chlorate (used in fireworks, flares and safety matches) forms oxygen and potassium chloride when heated.

KClO₃(s) KCl(s) + O₂(g) [unbalanced]

How many grams of oxygen are formed when 26.4 g of potassium chlorate is heated?

(_) 6.86 g

(_) 99.1 g

(_) 223 g

(_) 4.60 g

(o) 10.3 g

Silber4 3.TB.044.

Aluminum metal reacts with chlorine gas to form solid aluminum trichloride, AlCl₃. What mass of chlorine gas is needed to react completely with 163 g of aluminum?

(_) 321 g

(_) 245 g

(_) 214 g

(_) 489 g

(o) 643 g

Silber4 3.TB.045.

Lead(II) sulfide was once used in glazing earthenware. It will also react with hydrogen peroxide to form lead(II) sulfate and water. How many grams of hydrogen peroxide are needed to react completely with 265 g of lead(II) sulfide?

(_) 37.7 g

(_) 50.3 g

(_) 123 g

(_) 9.41 g

(o) 151 g

Silber4 3.TB.046.

An important reaction sequence in the industrial production of nitric acid is the following.

N₂(g) + 3 H₂(g) 2 NH₃(g)
4 NH₃(g) + 5 O₂(g) 4 NO(g) + 6 H₂O(l)

Starting from 20.0 mol of nitrogen gas in the first reaction, how many moles of oxygen gas are required in the second one?

(_) 25.0 mol O₂

(_) 20.0 mol O₂

(_) 12.5 mol O₂

(_) 100. mol O₂

(o) 50.0 mol O₂

Silber4 3.TB.047.

In a blast furnace, elemental iron is produced from a mixture of coke (C), iron ore (Fe₃O₄) and other reactants. An important reaction sequence is given below.

2 C(s) + O₂(g) 2 CO(g)
Fe₃O₄(s) + 4 CO(g) 3 Fe(l) + 4 CO₂(g)

How many moles of iron can be formed in this sequence when 1.00 mol of carbon, as coke, is consumed?

(_) 1.33 mol Fe

(_) 3.00 mol Fe

(_) 6.00 mol Fe

(_) 1.25 mol Fe

(o) 0.750 mol Fe

Silber4 3.TB.048.

Aluminum oxide (used as an adsorbent or a catalyst for organic reactions) forms when aluminum reacts with oxygen.

4 Al(s) + 3 O₂(g) 2 Al₂O₃(s)

A mixture of 82.49 g of aluminum (

= 26.98 g/mol) and 117.65 g of oxygen (

= 32.00 g/mol) is allowed to react. What mass of aluminum oxide (

= 101.96 g/mol) can be formed?

(_) 311.7 g

(_) 249.9 g

(_) 200.2 g

(_) 374.9 g

(o) 155.8 g

Silber4 3.TB.049.

Aluminum reacts with oxygen to produce aluminum oxide which can be used as an adsorbent, desiccant or catalyst for organic reactions.

4 Al(s) + 3 O₂(g) 2 Al₂O₃(s)

A mixture of 82.49 g of aluminum (

= 26.98 g/mol) and 117.65 g of oxygen (

= 32.00 g/mol) is allowed to react. Identify the limiting reactant and determine the mass of the excess reactant present in the vessel when the reaction is complete.

(_) Aluminum is the limiting reactant; 16.70 g of oxygen remain.

(_) Oxygen is the limiting reactant; 35.16 g of aluminum remain.

(_) Oxygen is the limiting reactant; 19.81 g of aluminum remain.

(_) Aluminum is the limiting reactant; 35.16 g of oxygen remain.

(o) Aluminum is the limiting reactant; 44.24 g of oxygen remain.

Silber4 3.TB.050.

Magnesium reacts with iron(III) chloride to form magnesium chloride (which can be used in fireproofing wood and in disinfectants) and iron.

3 Mg(s) + 2 FeCl₃(s) 3 MgCl₂(s) + 2 Fe(s)

A mixture of 41.0 g of magnesium (

= 24.31 g/mol) and 175 g of iron(III) chloride (

= 162.2 g/mol) is allowed to react. What mass of magnesium chloride (

= 95.21 g/mol) is formed?

(_) 71.4 g MgCl₂

(_) 77.0 g MgCl₂

(_) 68.5 g MgCl₂

(_) 107 g MgCl₂

(o) 154 g MgCl₂

Silber4 3.TB.051.

Magnesium (used in the manufacture of light alloys) reacts with iron(III) chloride to form magnesium chloride and iron.

3 Mg(s) + 2 FeCl₃(s) 3 MgCl₂(s) + 2 Fe(s)

A mixture of 41.0 g of magnesium (

= 24.31 g/mol) and 175 g of iron(III) chloride (

= 162.2 g/mol) is allowed to react. Identify the limiting reactant and determine the mass of the excess reactant present in the vessel when the reaction is complete.

(_) Limiting reactant is Mg; 104 g of FeCl₃ remain.

(_) Limiting reactant is Mg; 134 g of FeCl₃ remain.

(_) Limiting reactant is Mg; 67 g of FeCl₃ remain.

(_) Limiting reactant is FeCl₃; 87 g of Mg remain.

(o) Limiting reactant is FeCl₃; 2 g of Mg remain.

Silber4 3.TB.052.

Potassium chloride is used as a substitute for sodium chloride for individuals with high blood pressure. Identify the limiting reactant and determine the mass of the excess reactant remaining when 7.00 g of chlorine gas reacts with 5.00 g of potassium to form potassium chloride.

(_) Chlorine is the limiting reactant; 2.70 g of potassium remain.

(_) Chlorine is the limiting reactant; 4.64 g of potassium remain.

(_) Potassium is the limiting reactant; 7.23 g of chlorine remain.

(_) No limiting reagent: the reactants are present in the correct stoichiometric ratio.

(o) Potassium is the limiting reactant; 2.47 g of chlorine remain.

Silber4 3.TB.053.

Tetraphosphorus hexaoxide (

= 219.9 g/mol) is formed by the reaction of phosphorus with oxygen gas.

P₄(s) + 3 O₂(g) P₄O₆(s)

If a mixture of 75.3 g of phosphorus and 38.7 g of oxygen produce 43.3 g of P₄O₆, what is the percent yield for the reaction?

(_) 32.4%

(_) 38.0%

(_) 57.5%

(_) 16.3%

(o) 48.8%

Silber4 3.TB.054.

What is the percent yield for the following reaction if 119.3 g of PCl₅ (

= 208.2 g/mol) are formed when 61.3 g of Cl₂ (

= 70.91 g/mol) react with excess PCl₃?

PCl₃(g) + Cl₂(g) PCl₅(g)

(_) 51.4%

(_) 85.0%

(_) 195%

(_) 43.7%

(o) 66.3%

Silber4 3.TB.055.

Methanol (CH₄O) is converted to bromomethane (CH₃Br) as follows.

CH₄O + HBr CH₃Br + H₂O

If 12.23 g of bromomethane are produced when 5.00 g of methanol is reacted with excess HBr, what is the percentage yield?

(_) 100.%

(_) 245%

(_) 40.9%

(o) 82.6%

(_) 121%

Silber4 3.TB.056.

A 0.150 M sodium chloride solution is referred to as a physiological saline solution because it has the same concentration of salts as normal human blood. Calculate the mass of solute needed to prepare 275.0 mL of a physiological saline solution.

(_) 31.9 g

(_) 8.77 g

(_) 41.3 g

(o) 2.41 g

(_) 16.1 g

Silber4 3.TB.057.

Sodium chlorate is used as an oxidizer in the manufacture of dyes, explosives and matches. Calculate the mass of solute needed to prepare 1.575 L of 0.00250 M NaClO₃ (

= 106.45 g/mol).

(_) 169 g

(_) 0.00394 g

(_) 419 g

(o) 0.419 g

(_) 0.169 g

Silber4 3.TB.058.

Lithium hydroxide is used in alkaline batteries. Calculate the molarity of a solution prepared by dissolving 1.495 moles of LiOH in enough water to give a final volume of 750. mL.

(_) 1.12 M

(_) 0.00199 M

(_) 1.50 M

(o) 1.99 M

(_) 0.502 M

Silber4 3.TB.059.

Hydrochloric acid is widely used as a laboratory reagent, in refining ore for the production of tin and tantalum, and as a catalyst in organic reactions. Calculate the number of moles of HCl in 62.85 mL of 0.453 M hydrochloric acid.

(_) 1.04 mol

(_) 0.00721 mol

(_) 28.5 mol

(o) 0.0285 mol

(_) 0.139 mol

Silber4 3.TB.060.

Sodium hydroxide, also known as caustic soda, is used to neutralize acids and to treat cellulose in making of cellophane. Calculate the number of moles of solute in 1.875 L of 1.356 M NaOH solution.

(_) 0.7232 mol

(_) 0.001383 mol

(_) 1.383 mol

(o) 2.543 mol

(_) 0.3932 mol

Silber4 3.TB.061.

Calculate the molarity of a 23.55 mL solution which contains 28.24 mg of sodium sulfate (used in dyeing and printing textiles,

= 139.04 g/mol).

(_) 1.199 M

(_) 0.2031 M

(_) 8.625 M

(o) 0.008625 M

(_) 0.8339 M

Silber4 3.TB.062.

When 2.61 g of solid Na₂CO₃ is dissolved in sufficient water to make 250 mL of solution, what is the concentration of Na₂CO₃?

(_) 10.4 M

(_) 0.141 M

(_) 0.0246 M

(o) 0.0985 M₂

(_) 0.205 M

Silber4 3.TB.063.

Calcium chloride is used to melt ice and snow on roads and sidewalks and to remove water from organic liquids. Calculate the molarity of a solution prepared by diluting 165 mL of 0.688 M calcium chloride to 925.0 mL.

(_) 0.743 M

(_) 0.114 M

(_) 3.86 M

(o) 0.123 M

(_) 0.222 M

Silber4 3.TB.064.

What will be the final volume of a solution prepared by diluting 25 mL of 8.25 M sodium hydroxide to a concentration of 2.40 M?

(_) 210 mL

(_) 7.3 mL

(_) 330 mL

(o) 86 mL

(_) 60 mL

Silber4 3.TB.065.

What volume, in L, of 10.0 M HCl is needed to make 2.00 L of 2.00 M HCl solution by dilution with water?

(_) 0.200 L

(_) none of these

(_) 0.800 L

(o) 0.400 L

(_) 0.100 L

Silber4 3.TB.066.

How many mL of concentrated nitric acid (HNO₃, 16.0 M) should be diluted with water in order to make 2.00 L of 2.00 M solution?

(_) 62.5 mL

(_) 500. mL

(_) 32.0 mL

(o) 250. mL

(_) 125 mL

Silber4 3.TB.067.

How many milliliters of 1.58 M HCl are needed to react completely with 23.2 g of NaHCO₃ (

= 84.02 g/mol)?

HCl(aq) + NaHCO₃(s) NaCl(s) + H₂O(l) + CO₂(g)

(_) 572 mL

(_) 276 mL

(_) 638 mL

(o) 175 mL

(_) 536 mL

Silber4 3.TB.068.

Copper(II) sulfide, CuS, is used in the development of aniline black dye in textile printing. What is the maximum mass of CuS which can be formed when 38.0 mL of 0.500 M CuCl₂ are mixed with 42.0 mL of 0.600 M (NH₄)₂S? Aqueous ammonium chloride is the other product.

(_) 1.21 g

(_) 0.044 g

(_) 2.41 g

(o) 1.82 g

(_) 0.909 g

Silber4 3.TB.069.

What mass of carbon is needed to react with 10.00 g of SnO₂(s) according to the following chemical equation: SnO₂(s) + 2 C(s)

Sn(s) + 2 CO(g)?

(_) 7.94 g

(_) 23.8 g

(_) 3.97 g

(o) 1.59 g