Chapter 4 2 What is the mass percentage of barium chloride

62. If all of the chloride in a 3.734-g sample of an unknown metal chloride is precipitated as

AgCl with 70.90 mL of 0.2010 M AgNO3, what is the percentage of chloride in the sample?

A)

50.52%

B)

13.53%

C)

1.425%

D)

7.391%

E)

none of the above

63. A mixture of BaCl2 and NaCl is analyzed by precipitating all the barium as BaSO4. After

addition of an excess of Na2SO4 to a 3.725-g sample of the mixture, the mass of precipitate

collected is 2.734 g. What is the mass percentage of barium chloride in the mixture?

A)

82.28%

B)

73.40%

C)

43.18%

D)

65.47%

E)

19.60%

64. A 3.00-g sample of an alloy (containing only Pb and Sn) was dissolved in nitric acid

(HNO3). Sulfuric acid was added to this solution, which precipitated 2.37 g of PbSO4.

Assuming that all of the lead was precipitated, what is the percentage of Sn in the sample?

(molar mass of PbSO4 = 303.3 g/mol)

A)

46.0% Sn

B)

0.781% Sn

C)

79.0% Sn

D)

54.0% Sn

E)

1.62% Sn

65. A mixture contained no fluorine compound except methyl fluoroacetate, FCH2COOCH3

(molar mass = 92.07 g/mol). When chemically treated, all the fluorine was converted to

CaF2 (molar mass = 78.08 g/mol). The mass of CaF2 obtained was 35.8 g. Find the mass of

methyl fluoroacetate in the original mixture.

A)

60.7 g

B)

84.4 g

C)

30.4 g

D)

42.2 g

E)

21.1 g

66. A 1.59-g sample of a metal chloride, MCl2, is dissolved in water and treated with excess

aqueous silver nitrate. The silver chloride that formed weighed 3.60 g. Calculate the molar

mass of M.

A)

70.9 g/mol

B)

28 g/mol

C)

55.9 g/mol

D)

63 g/mol

E)

72.4 g/mol

67. You have 88.6 mL of a 2.50 M solution of Na2CrO4(aq). You also have 125 mL of a 2.50 M

solution of AgNO3(aq). Calculate the concentration of Na+ after the two solutions are mixed

together.

A)

0.00 M

B)

1.04 M

C)

2.07 M

D)

5.00 M

E)

0.443 M

68. You have 75.0 mL of a 2.50 M solution of Na2CrO4(aq). You also have 125 mL of a 2.01 M

solution of AgNO3(aq). Calculate the concentration of CrO42– after the two solutions are

mixed together.

A)

0.00 M

B)

0.309 M

C)

0.938 M

D)

0.251 M

E)

2.50 M

69. You have 75.0 mL of a 2.50 M solution of Na2CrO4(aq). You also have 125 mL of a 1.72 M

solution of AgNO3(aq). Calculate the concentration of Ag+ after the two solutions are mixed

together.

A)

0.00 M

B)

0.538 M

C)

1.08 M

D)

0.088 M

E)

0.215 M

70. You have 75.0 mL of a 2.50 M solution of Na2CrO4(aq). You also have 125 mL of a 1.88 M

solution of AgNO3(aq). Calculate the concentration of NO3– after the two solutions are

mixed together.

A)

0.00 M

B)

0.588 M

C)

1.18 M

D)

2.35 M

E)

4.50 M

71. You mix 55 mL of 1.00 M silver nitrate with 25 mL of 0.84 M sodium chloride. What mass

of silver chloride should you form?

A)

3.0 g

B)

6.0 g

C)

3.3 g

D)

6.6

E)

none of these

72. When solutions of carbonic acid and potassium hydroxide react, which of the following are

NOT present in the complete ionic equation?

A)

hydrogen ion

B)

carbonate ion

C)

potassium ion

D)

hydroxide ion

E)

water

73. When solutions of acetic acid and sodium hydroxide react, which of the following are NOT

present in the net ionic equation?

I.

hydrogen ion

II.

acetate ion

III.

sodium ion

IV.

hydroxide ion

A)

I and II

B)

I, II, and III

C)

I and IV

D)

I and III

E)

II and III

74. When solutions of carbonic acid and aluminum hydroxide react, which of the following are

NOT present in the net ionic equation?

I.

hydrogen ion

II.

carbonate ion

III.

aluminum ion

IV.

hydroxide ion

A)

I and II

B)

I, II, and III

C)

I and IV

D)

I and III

E)

II and III

75. When solutions of carbonic acid and copper(II) hydroxide react, which of the following are

spectator ions?

A)

hydrogen ion

B)

carbonate ion

C)

copper(II) ion

D)

hydroxide ion

E)

none of these

76. In the balanced molecular equation for the neutralization of sodium hydroxide with sulfuric

acid, the products are:

A)

NaSO4 + H2O

B)

NaSO3 + 2H2O

C)

2NaSO4 + H2O

D)

Na2S + 2H2O

E)

Na2SO4 + 2H2O

77. A 0.307-g sample of an unknown triprotic acid is titrated to the third equivalence point

using 35.2 mL of 0.106 M NaOH. Calculate the molar mass of the acid.

A)

247 g/mol

B)

171 g/mol

C)

165 g/mol

D)

151 g/mol

E)

82.7 g/mol

78. An unknown diprotic acid requires 44.39 mL of 0.111 M NaOH to completely neutralize a

0.580-g sample. Calculate the approximate molar mass of the acid.

A)

406 g/mol

B)

235 g/mol

C)

118 g/mol

D)

59 g/mol

E)

203 g/mol

79. You have separate solutions of HCl and H2SO4 with the same concentrations in terms of

molarity. You wish to neutralize a solution of NaOH. Which acid solution would require

more volume (in mL) to neutralize the base?

A)

The HCl solution.

B)

The H2SO4 solution.

C)

You need to know the acid concentrations to answer this question.

D)

You need to know the volume and concentration of the NaOH solution to answer

this question.

E)

C and D

80. What mass of NaOH is required to react exactly with 25.0 mL of 2.7 M H2SO4?

A)

2.7 g

B)

0.7 g

C)

5.4 g

D)

135 g

E)

none of these

81. With what volume of 5.00 M HF will 4.72 g of calcium hydroxide react completely,

according to the following reaction?

A)

12.7 mL

B)

127 mL

C)

637 mL

D)

25.5 mL

E)

39.2 mL

82. Sulfamic acid, HSO3NH2 (molar mass = 97.1 g/mol), is a strong monoprotic acid that can be

used to standardize a strong base:

A 0.165-g sample of HSO3NH2 required 19.4 mL of an aqueous solution of KOH for a

complete reaction. What is the molarity of the KOH solution?

A)

0.00170 M

B)

8.76 M

C)

0.0876 M

D)

0.0330 M

E)

none of these

83. A student weighs out 0.512 g of KHP (molar mass = 204.22 g/mol) and titrates to the

equivalence point with 36.78 mL of a stock NaOH solution. What is the concentration of the

stock NaOH solution? KHP is an acid with one acidic proton.

A)

0.00251 M

B)

0.092 M

C)

0.0139 M

D)

0.0682 M

E)

none of these

84. A chemical that changes color at the endpoint of a reaction is called a colorimeter.

85. In which of the following does nitrogen have an oxidation state of +4?

A)

HNO3

B)

NO2

C)

N2O

D)

NH4Cl

E)

NaNO2

86. The oxidation state of iodine in IO3– is:

A)

0

B)

+3

C)

–3

D)

+5

E)

–5

87. The oxidation state of chlorine in ClO– is:

A)

0

B)

+1

C)

-1

D)

+3

E)

-3

88. Which of the following statements is not true?

A)

When a metal reacts with a nonmetal, an ionic compound is formed.

B)

A metal-nonmetal reaction can always be assumed to be an oxidation-reduction

reaction.

C)

Two nonmetals can undergo an oxidation-reduction reaction.

D)

When two nonmetals react, the compound formed is ionic.

E)

A metal-nonmetal reaction involves electron transfer.

89. In the reaction 2Ca(s) + O2(g) → 2CaO(s), which species is oxidized?

A)

O2

B)

O2–

C)

Ca

D)

Ca2+

E)

none of these

90. In the reaction 2Cs(s) + Cl2(g) → 2CsCl(s), Cl2 is

A)

the reducing agent

B)

the oxidizing agent

C)

oxidized

D)

the electron donor

E)

two of these

91. In the reaction N2(g) + 3H2(g) → 2NH3(g), N2 is

A)

oxidized

B)

reduced

C)

the electron donor

D)

the reducing agent

E)

two of these

92. In the reaction P4(s) + 10Cl2(g) → 4PCl5(s), the reducing agent is

A)

chlorine

B)

PCl5

C)

phosphorus

D)

Cl–

E)

none of these

93. In the reaction C(s) + O2(g) → CO2(g) carbon is __________.

A)

the reducing agent

B)

the electron acceptor

C)

reduced

D)

the oxidizing agent

E)

more than one of these

94. Which of the following reactions does not involve oxidation-reduction?

A)

CH4 + 3O2 → 2H2O + CO2

B)

Zn + 2HCl → ZnCl2 + H2

C)

2Na + 2H2O → 2NaOH + H2

D)

MnO2 + 4HCl → Cl2 + 2H2O + MnCl2

E)

All are oxidation-reduction reactions.

95. Which of the following are oxidation-reduction reactions?

I.

PCl3 + Cl2 → PCl5

II.

Cu + 2AgNO3 → Cu(NO3)2 + 2Ag

III.

CO2 + 2LiOH → Li2CO3 + H2O

IV.

FeCl2 + 2NaOH → Fe(OH)2 + 2NaCl

A)

III

B)

IV

C)

I and II

D)

I, II, and III

E)

I, II, III, and IV

96. Which of the following statements is(are) true? Oxidation and reduction

A)

cannot occur independently of each other

B)

accompany all chemical changes

C)

describe the loss and gain of electron(s), respectively

D)

result in a change in the oxidation states of the species involved

E)

A, C, and D

97. In the reaction Zn + H2SO4 → ZnSO4 + H2, which, if any, element is oxidized?

A)

zinc

B)

hydrogen

C)

sulfur

D)

oxygen

E)

none of these

98. In the following reaction, which species is oxidized?

8NaI + 5H2SO4 → 4I2 + H2S + 4Na2SO4 + 4H2O

A)

sodium

B)

iodine

C)

sulfur

D)

hydrogen

E)

oxygen

99. How many of the following are oxidation-reduction reactions?

NaOH + HCl → NaCl + H2O

Cu + 2AgNO3 → 2Ag + Cu(NO3)2

Mg(OH)2 → MgO + H2O

N2 + 3H2 → 2NH3

A)

0

B)

1

C)

2

D)

3

E)

4

100. In the reaction shown below, what species is oxidized?

2NaI + Br2 → 2NaBr + I2

A)

Na+

B)

I–

C)

Br2

D)

Br–

E)

I2

101. Oxidation is the gain of electrons.

102. A reducing agent is an electron donor.

103. Balance the following oxidation-reduction reaction using the oxidation number method:

Fe3+ + I– → Fe2+ + I2

In the balanced equation, the coefficient of Fe2+ is

A)

1

B)

2

C)

3

D)

4

E)

none of these

104. Balance the following oxidation-reduction reaction using the oxidation number method:

Fe + Br2 → Fe3+ + Br–

In the balanced equation, the coefficient of Br– is

A)

2

B)

3

C)

4

D)

6

E)

none of these

105. Consider the following unbalanced oxidation-reduction reaction:

Fe2+ + Br2 → Fe3+ + Br–

In the balanced equation, the number of electrons transferred is

A)

1

B)

3

C)

2

D)

4

E)

none of these

106. The MnO4– is often used to analyze for the Fe2+ content of an aqueous solution via the

reaction

MnO4–(aq) + Fe2+(aq) + H+(aq) → Fe3+(aq) + Mn2+(aq) + H2O(l)

What is the ratio of Fe2+ : MnO4– in the balanced equation?

A)

1 : 1

B)

2 : 1

C)

3 : 1

D)

4 : 1

E)

5 : 1

107. Given the reaction:

2MnO4– + 5H2O2 + 6H+ → 2Mn2+ + 8H2O + 5O2

determine the number of electrons involved in this reaction.

A)

10

B)

8

C)

6

D)

4

E)

2

108. A molecule with an unequal charge distribution is said to be a __________ molecule.

109. Soluble ionic compounds containing the hydroxide ion are called strong __________.

110. A __________ is a substance dissolved in a liquid to make a solution.

111. A __________ electrolyte dissociates to a great extent in an aqueous solution.

112. Molarity is defined as __________ of solute per volume of solution in ___________.

113. Cu(OH)2(s)

114. FeCl3(aq) + Na2SO4(aq)

115. Precipitation of BaSO4 from solution

116. Neutralization of sulfuric acid

117. Combustion reaction

118. Dissolution of calcium hydroxide with another reagent

119. Formation of hydrogen gas

120. Balance the following equation: C3H5(NO3)3 → N2 + CO2 + H2O + O2

121. Balance the following equation: KI + HNO3 → KNO3 + NO + I2 + H2O