Chapter 4 3 What is the molarity of a potassium triiodide solution

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91) What is the molarity of a potassium triiodide solution, KI3(aq), if 30.00 mL of the solution is

required to completely react with 25.00 mL of a 0.200 M thiosulfate solution, K2S2O3(aq)? The

chemical equation for the reaction is

2 S2O32-(aq) + I3–(aq) → S4O62-(aq) + 3 I–(aq).

A) 0.0833 M

B) 0.120 M

C) 0.167 M

D) 0.333 M

92) Based on the balanced chemical equation shown below, determine the molarity of a solution

containing Fe2+(aq), if 40.00 mL of the Fe2+(aq) solution is required to completely react with 30.00 mL

of a 0.250 M potassium bromate, KBrO3(aq), solution. The chemical equation for the reaction is

6 Fe2+(aq) + BrO3–(aq) + 6 H+(aq) → 6 Fe3+(aq) + Br–(aq) + 3 H2O(l).

A) 0.0312 M

B) 0.188 M

C) 1.12 M

D) 2.00 M

93) Based on the balanced chemical equation shown below, determine the mass percent of Fe3+ in a

0.7450 g sample of iron ore, if 22.40 mL of a 0.1000 M stannous chloride, SnCl2(aq), solution is

required to completely react with the Fe3+ present in the ore sample. The chemical equation for the

reaction is

2 Fe3+(aq) + Sn2+(aq) → 2 Fe2+(aq) + Sn4+(aq).

A) 5.365%

B) 8.396%

C) 16.79%

D) 33.58%

94) How many grams of H2 gas can be produced by the reaction of 54.0 grams of Al(s) with an excess

of dilute hydrochloric acid in the reaction shown below?

2 Al(s) + 6 HCl(aq) → 2 AlCl3(aq) + 3 H2(g)

A) 2.68 g

B) 4.04 g

C) 6.05 g

D) 12.1 g

95) Which of the following solutions will have the highest electrical conductivity?

A) 0.045 M Al2(SO4)3

B) 0.050 M (NH4)2CO3

C) 0.10 M NaBr

D) 0.10 M NaI

E) 0.10 M NaF

96) Which one of the following compounds behaves as an acid when dissolved in water?

A) RaO

B) C4H10

C) HI

D) RbOH

97) Which of the compounds of H2C2O4, Ca(OH)2, KOH, and HI, behave as acids when they are

dissolved in water?

A) Ca(OH)2 and KOH

B) H2C2O4 and HI

C) only HI

D) only KOH

98) Which of the compounds H2C2O4, Ca(OH)2, KOH, and HI, behave as bases when they are

dissolved in water?

A) Ca(OH)2 and KOH

B) H2C2O4 and HI

C) only HI

D) only KOH

99) When dissolved in water, KOH behaves as

A) an acid that forms K+ and OH– ions.

B) an acid that forms KO– and H+ ions.

C) a base that forms K+ and OH– ions.

D) a base that forms KO– and H+ ions.

100) H Cl , HI , H2SO4, Li Cl , and KI are all classified as

A) acids.

B) nonelectrolytes.

C) strong electrolytes.

D) weak electrolytes.

101) Which of the following is NOT a strong electrolyte?

A) NaOH

B) CaCl2

C) CaCO3

D) NaC2H3O2

E) K2SO4

102) Which of the following is considered a STRONG electrolyte?

A) NH4NO3

B) C12H22O11

C) PbBr2

D) HC2H3O2

E) CH3SH

103) Identify water.

A) strong electrolyte, weak acid

B) weak electrolyte, weak acid

C) strong electrolyte, strong acid

D) weak electrolyte, strong acid

E) nonelectrolyte

104) Identify LiBr.

A) weak acid

B) weak electrolyte

C) strong acid

D) strong electrolyte

E) nonelectrolyte

105) Which one of the following compounds is insoluble in water?

A) Ca Cl2

B) NaNO3

C) Pb Cl2

D) K2CO3

106) Which one of the following compounds is soluble in water?

A) Cu3(PO4)2

B) CoS

C) Pb(NO3)2

D) ZnCO3

107) Which pair of compounds is soluble in water?

A) Ag Cl and AgBr

B) CoS and K2S

C) NaI and Cu(NO3)2

D) NH4NO3 and BaCO3

108) How many of the following compounds are soluble in water?

Cu(OH)2 NaNO3 NH4Cl Li2S

A) 0

B) 1

C) 2

D) 3

E) 4

109) Which of the following compounds is soluble in water?

A) CaS

B) MgCO3

C) PbBr2

D) PbSO4

E) None of these compounds is soluble in water.

110) Which of the following compounds is insoluble in water?

A) Hg2Cl2

B) MgSO4

C) (NH4)2CO3

D) SrS

E) All of these compounds are soluble in water.

111) How many of the following compounds are insoluble in water?

NaC2H3O2 SrSO4 BaS AlPO4

A) 0

B) 1

C) 2

D) 3

E) 4

112) What precipitate is most likely formed from a solution containing Ba+2, Li+1, OH-1, and CO3-2.

A) LiOH

B) BaCO3

C) Li2CO3

D) Ba(OH)2

113) The mixing of which pair of reactants will result in a precipitation reaction?

A) CsI(aq) + NaOH(aq)

B) HCl(aq) + Ca(OH)2(aq)

C) K2SO4(aq) + Hg2(NO3)2(aq)

D) NaNO3(aq) + NH4Cl(aq)

114) The mixing of which pair of reactants will result in a precipitation reaction?

A) Ba(NO3)2(aq) + Na2CO3(aq)

B) K2SO4(aq) + Cu(NO3)2(aq)

C) NaClO4(aq) + (NH4)2S(aq)

D) NH4Br(aq) + NH4I(aq)

115) What reagent could be used to separate Br– from CH3CO2– when added to an aqueous solution

containing both?

A) AgNO3(aq)

B) Ba(OH)2(aq)

C) CuSO4(aq)

D) NaI(aq)

116) What reagent could not be used to separate Br– from CO32- when added to an aqueous solution

containing both?

A) AgNO3(aq)

B) Ca(NO3)2(aq)

C) Cu(NO3)2(aq)

D) Fe(NO3)2(aq)

117) Which of the following is a precipitation reaction?

A) Zn(s) + 2 AgNO3(aq) → 2 Ag(s) + Zn(NO3)2(aq)

B) NaCl(aq) + LiI(aq) → NaI(aq) + LiCl(aq)

C) 2 KI(aq) + Hg2(NO3)2(aq) → Hg2I2(s) + 2 KNO3(aq)

D) HI(aq) + NaOH(aq) → NaI(aq) + H2O(l)

E) None of the above are precipitation reactions.

118) Which of the following pairs of aqueous solutions will form a precipitate when mixed?

A) HI+ LiOH

B) Li2S + HF

C) K2CO3 + HNO3

D) MgCl2 + KOH

E) All of these solution pairs will produce a precipitate.

119) Which of the following pairs of aqueous solutions will form a precipitate when mixed?

A) K2CO3 + NaBr

B) Na2 SO4 + KOH

C) CaS + Na2SO4

D) None of these solution pairs will produce a precipitate.

E) All of these solution pairs will produce a precipitate.

120) Which of the following pairs of aqueous solutions will form a precipitate when mixed?

A) NH4NO3 + Li2CO3

B) Hg2(NO3)2 + LiCl

C) NaCl + Li3PO4

D) AgC2H3O2 + Cu(NO3)2

E) None of the above solution pairs will produce a precipitate.

121) Which of the following pairs of aqueous solutions will form a precipitate when mixed?

A) KOH + Li2S

B) (NH4)2SO4 + KCl

C) Sr(C2H3O2)2 + Na2SO4

D) KNO3 + LiOH

E) None of the above solution pairs will produce a precipitate.

122) Lead ions can be precipitated from aqueous solutions by the addition of aqueous iodide:

Pb2+ (aq) + 2I– (aq) → PbI2 (s)

Lead iodide is virtually insoluble in water so that the reaction appears to go to completion. How many

milliliters of 3.550 M HI(aq) must be added to a solution containing 0.700 mol of Pb(NO3)2 (aq) to

completely precipitate the lead?

A) 2.54 × 10-3 mL

B) 394 mL

C) 197 mL

D) 0.197 mL

E) 0.394 mL

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123) Silver ions can be precipitated from aqueous solutions by the addition of aqueous chloride:

Ag+ (aq) + Cl– (aq) → AgCl(s)

Silver chloride is virtually insoluble in water so that the reaction appears to go to completion. How many

grams of solid NaCl must be added to 25.0 mL of 0.366 M AgNO3 solution to completely precipitate

the silver?

A) 9.15 × 10-3 g

B) 1.57 × 10-4 g

C) 0.535 g

D) 0.157 g

E) 6.39 × 103 g

124) Identify the spectator ions in the following molecular equation.

LiCl(aq) + AgNO3(aq) → AgCl(s) + LiNO3(aq)

A) Ag+ and Cl–

B) Li+ and NO3–

C) Li+ and Cl–

D) Ag+ and NO3–

E) There are no spectator ions in this reaction.

125) Identify the polyprotic acid.

A) H2SO4

B) HCl

C) LiCl

D) LiOH

E) Ca(OH)2

126) How many H+ ions can the acid, H2SO4 , donate per molecule?

A) 0

B) 1

C) 2

D) 3

127) Which of the following compounds is not an Arrhenius acid?

A) CH3CO2H

B) CH3CH2NH2

C) HNO2

D) H2SO4

128) Which of the following compounds is an Arrhenius base?

A) C6H12O6

B) HOCl

C) H2SO4

D) C6H5NH2

129) Which of the following compounds is an Arrhenius base?

A) CH3OH

B) CH3CO2H

C) HOCl

D) CsOH

130) In an acid-base neutralization reaction 38.74 mL of 0.500 M potassium hydroxide reacts with 50.00

mL of sulfuric acid solution. What is the concentration of the H2SO4 solution?

A) 0.194 M

B) 0.387 M

C) 0.775 M

D) 1.29 M

131) When 280. mL of 1.50 × 10-4 M hydrochloric acid is added to 135 mL of 1.75 × 10-4 M

Mg(OH)2, the resulting solution will be

A) acidic.

B) basic

C) neutral.

D) It is impossible to tell from the information given.

132) A solution is prepared by mixing 50.0 mL of 0.100 M HCl and 10.0 mL of 0.200 M NaCl. What is

the molarity of chloride ion in this solution?

A) 0.183

B) 8.57

C) 3.50

D) 0.0500

E) 0.117

133) A solution is prepared by adding 1.60 g of solid NaCl to 50.0 mL of 0.100 M CaCl2. What is the

molarity of chloride ion in the final solution? Assume that the volume of the final solution is 50.0 mL.

A) 0.747

B) 0.647

C) 0.132

D) 0.232

E) 0.547

134) What is the molarity of a NaOH solution if 28.2 mL of a 0.355 M H2SO4 solution is required to

neutralize a 25.0-mL sample of the NaOH solution?

A) 0.801

B) 0.315

C) 0.629

D) 125

E) 0.400

135) How many milliliters of 0.132 M HClO4 solution are needed to neutralize 50.00 mL of 0.0789 M

NaOH?

A) 0.521

B) 0.0120

C) 83.7

D) 0.0335

E) 29.9

136) What is the oxidation number of the sulfur atom in K2SO4 ?

A) -2

B) +2

C) +4

D) +6

137) What is the oxidation number of the chromium atom in K2CrO4 ?

A) -2

B) +2

C) +6

D) +7

138) Determine the oxidation state of nitrogen in KNO3.

A) +5

B) +3

C) 0

D) +2

E) +4

139) Determine the oxidation state of nitrogen in KNO2.

A) +5

B) +3

C) 0

D) +2

E) +4

140) Determine the oxidation state of hydrogen in H2.

A) +5

B) +3

C) 0

D) +2

E) +4

141) What is the oxidation number of the oxygen atom in Na2O2 ?

A) -2

B) -1

C) +1

D) +2

142) What is the oxidation number change for the bromine atom in the following unbalanced reduction

half reaction:

Br O3– (aq) + H+(aq) → Br–(aq) + H2O(l)?

A) -7

B) -6

C) +6

D) +7

143) Determine the oxidation state of Cr in Cr(SO4)2.

A) +2

B) +4

C) +6

D) 0

E) -2

144) Determine the oxidation state of S in Na2SO4.

A) -4

B) +2

C) +4

D) +6

E) -2

145) Identify the oxidation state of Ba in Ba(s).

Ba(s) + 2HF(aq) → BaF2(aq) + H2(g)

A) +1

B) +2

C) 0

D) -1

E) -2

146) Identify the oxidation state of H in HF(aq).

Mg(s) + 2HF(aq) → MgF2(aq) + H2(g)

A) +1

B) +2

C) 0

D) -1

E) -2

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147) Identify the oxidation state of Ba in BaCl2(aq).

Ba(s) + 2HCl(aq) → BaCl2(aq) + H2(g)

A) +1

B) +2

C) 0

D) -1

E) -2

148) Identify the oxidation state of H in H2(g).

Mg(s) + 2HI(aq) → MgI2(aq) + H2(g)

A) +1

B) +2

C) 0

D) -1

E) -2

149) Which of the following is an oxidation-reduction reaction?

A) HI(aq) + LiOH(aq) → LiI(aq) + H2O(l)

B) NaCl(aq) + AgNO3(aq) → AgCl(s) + NaNO3(aq)

C) Pb(C2H3O2)2(aq) + 2 NaCl(aq) → PbCl2(s) + 2 NaC2H3O2(aq)

D) Mg(s) + 2 HCl(aq) → MgCl2(aq) + H2(g)

E) All of the above are oxidation-reduction reactions.

150) What are the coefficients in front of NO3–(aq) and Cu(s) when the following redox equation is

balanced in an acidic solution:

___ NO3–(aq) + ___ Cu(s) → ___ NO(g) + ___ Cu2+(aq)?

A) 2, 3

B) 2, 6

C) 3, 4

D) 3, 6

Answer: A

Diff: 2 Page Ref: 4.9

Matching Questions

Match the following.

A) precipitation

B) gas evolution

C) acid-base

D) combustion

E) oxidation reduction

1) CH4(g) + 2 O2(g) → CO2(g) + 2 H2O(g)

Diff: 1 Page Ref: 4.9

2) H2SO4(aq) + 2 LiOH(aq) → 2 H2O(l) + Li2SO4(aq)

Diff: 1 Page Ref: 4.8

3) Mg(s) + Cu(NO3)2(aq) → Mg(NO3)2(aq) + Cu(s)

Diff: 1 Page Ref: 4.9

4) HCl(aq) + (NH4)2S(aq) → H2S(g) + 2NH4Cl(aq)

Diff: 1 Page Ref: 4.8

5) NaCl(aq) + AgNO3(aq) → AgCl(s) + NaNO3(aq)

Diff: 1 Page Ref: 4.6

Short Answer Questions

1) Describe the greenhouse effect.

2) Define a limiting reagent.

3) How would the concentration change if a 1.0 L flask of 1.0 M NaCl were left uncapped on a

laboratory bench for several days. Why?

4) Define an electrolyte.

5) Explain the difference between a strong and weak electrolyte. Give an example of each.

6) What causes a precipitation reaction to occur between two soluble compounds?

7) Describe the difference between complete ionic and net ionic equations.

8) Define a spectator ion.

9) List the spectator ions in the following reaction.

Ba+2(aq) + 2 OH–(aq) + 2 Na +(aq) + CO3 -2(aq) → 2 Na +(aq) + 2 OH–(aq) + BaCO3(s)

10) How can you tell if a reaction is an oxidation-reduction reaction?

11) Determine the oxidation state of Mn in KMnO4.