Question 1

Which of the following combinations is correct?

Accepted Answer

A)  NaOH/weak base 
B)  H3PO4/strong acid 
C)  HNO3/weak acid 
D)  NH3/strong base 
E)  HClO4/strong acid 
A)  NaOH/weak base 
B)  H3PO4/strong acid 
C)  HNO3/weak acid 
D)  NH3/strong base 
E)  HClO4/strong acid

Question 2

Gold does not react with either nitric acid or hydrochloric acid but with a combination of both called aqua regia. Identify the oxidizing agent in the following equation: Au(s) + 4 H+ + NO3- + 4 Cl- → [AuCl4]- + 2 H2O + NO(g)

Accepted Answer

A)  Au 
B)  H+ 
C)  NO3- 
D)  Cl- 
E)  NO3- and H+ 
A)  Au 
B)  H+ 
C)  NO3- 
D)  Cl- 
E)  NO3- and H+

Question 3

A 0.411 g sample of powdered copper mixed with an inert, soluble additive was fully consumed by 23.4 mL of 0.602 M nitric acid, producing copper(II) nitrate, water, and nitric oxide (NO) gas. What was the percent copper (by mass) in the sample? 3 Cu + 8 HNO3 → 3 Cu(NO3)2 + 2 NO + 4 H2O

Accepted Answer

A)  81.7% 
B)  68.3% 
C)  65.3% 
D)  56.9% 
E)  34.4% 
A)  81.7% 
B)  68.3% 
C)  65.3% 
D)  56.9% 
E)  34.4%

Question 4

Which of the following is probably the poorest electrical conductor?

Accepted Answer

A)  0.5 M K2SO4 
B)  0.5 M CaCl2 
C)  0.5 M HF 
D)  0.5 M CH3OH 
E)  0.5 M NH3 
A)  0.5 M K2SO4 
B)  0.5 M CaCl2 
C)  0.5 M HF 
D)  0.5 M CH3OH 
E)  0.5 M NH3

Question 5

Balance the following equation in basic solution: Cr3+ + O22- → CrO42-
The sum of the coefficients is ________.

Accepted Answer

A)  13 
B)  53 
C)  27 
D)  18 
E)  38 
A)  13 
B)  53 
C)  27 
D)  18 
E)  38

Question 6

For redox reactions to be balanced, electrons should be present on the reactant side.

Accepted Answer

A) True 
 B)False

Question 7

Which of the following pairs of aqueous solutions will give a precipitate when mixed?

Accepted Answer

A)  K3PO4 and CaCl2 
B)  LiClO4 and Ba(OH)2 
C)  AgNO3 and Ca(ClO4)2 
D)  NaCl and K(CH3COO) 
E)  Sr(NO3)2 and KI 
A)  K3PO4 and CaCl2 
B)  LiClO4 and Ba(OH)2 
C)  AgNO3 and Ca(ClO4)2 
D)  NaCl and K(CH3COO) 
E)  Sr(NO3)2 and KI

Question 8

Complete the equation and indicate if a precipitate forms. Na+ + Cl- + NO3- + K+ →

Accepted Answer

A)  NaCl(s) + NO3- + K+ 
B)  NaNO3(s) + K+ + Cl- 
C)  KCl(s) + Na+ + NO3- 
D)  KNO3(s) + Na+ + Cl- 
E)  no reaction 
A)  NaCl(s) + NO3- + K+ 
B)  NaNO3(s) + K+ + Cl- 
C)  KCl(s) + Na+ + NO3- 
D)  KNO3(s) + Na+ + Cl- 
E)  no reaction

Question 9

Assuming that the proposed reactants are mixed in stoichiometric ratios, and at moderate concentrations, which of the following is least likely to represent an observable (e.g., gas evolution or precipitation) reaction?

Accepted Answer

A)  Ca2+ + 2 Cl- + 2 K+ + CO32- → ? 
B)  2 Na+ + CO32- + 2 HC2N3O2 → ? 
C)  H2S + Cu2+ + SO42- → ? 
D)  H2SO3 + Li+ + Cl- → ? 
E)  Pb2+ + 2 NO3- + 2 Na+ + 2 OH- → ? 
A)  Ca2+ + 2 Cl- + 2 K+ + CO32- → ? 
B)  2 Na+ + CO32- + 2 HC2N3O2 → ? 
C)  H2S + Cu2+ + SO42- → ? 
D)  H2SO3 + Li+ + Cl- → ? 
E)  Pb2+ + 2 NO3- + 2 Na+ + 2 OH- → ?

Question 10

In which of the following pairs is the oxidation number for the underlined element INCORRECT?

Accepted Answer

A)  MnO2/(+4 ) 
B)  SO32-/(+4) 
C)  ClO3-/(+7) 
D)  NO2-/(+3) 
E)  Cr2O3/(+3) 
A)  MnO2/(+4 ) 
B)  SO32-/(+4) 
C)  ClO3-/(+7) 
D)  NO2-/(+3) 
E)  Cr2O3/(+3)

Question 11

Balance the following equation in basic solution: Br2 + Mn2+ → MnO2 + Br-
The sum of the coefficients is ________.

Accepted Answer

A)  8 
B)  15 
C)  12 
D)  17 
E)  11 
A)  8 
B)  15 
C)  12 
D)  17 
E)  11

Question 12

Which of the following would have the strongest tendency of producing OH- ions in an aqueous solution?

Accepted Answer

A)  Fe(OH)2 
B)  Fe(OH)3 
C)  Ba(OH)2 
D)  NaOH 
E)  HOCl 
A)  Fe(OH)2 
B)  Fe(OH)3 
C)  Ba(OH)2 
D)  NaOH 
E)  HOCl

Question 13

The substance CH3COOH in water is a:

Accepted Answer

A)  strong electrolyte 
B)  weak electrolyte 
C)  nonelectrolyte 
D)  strong acid 
E)  strong base 
A)  strong electrolyte 
B)  weak electrolyte 
C)  nonelectrolyte 
D)  strong acid 
E)  strong base

Question 14

Balance the following equation for an oxidation-reduction reaction occurring in an acidic solution: HNO3 + I2 → HIO3 + NO2 + H2O
The sum of the coefficients is ________.

Accepted Answer

A)  26 
B)  27 
C)  28 
D)  33 
E)  45 
A)  26 
B)  27 
C)  28 
D)  33 
E)  45

Question 15

Which of the following compounds is quite insoluble in water, but would liberate a gas when treated with aqueous acetic acid?

Accepted Answer

A)  K2CO3 
B)  K2SO4 
C)  CaCO3 
D)  CaSO4 
E)  AgCl 
A)  K2CO3 
B)  K2SO4 
C)  CaCO3 
D)  CaSO4 
E)  AgCl

Question 16

In which of the following pairs is the oxidation number for the underlined element INCORRECT?

Accepted Answer

A)  MnO4-/(+7 ) 
B)  SO42-/(+4) 
C)  NH4+/(-3) 
D)  NO3-/(+5) 
E)  Cr2O72-/(+6) 
A)  MnO4-/(+7 ) 
B)  SO42-/(+4) 
C)  NH4+/(-3) 
D)  NO3-/(+5) 
E)  Cr2O72-/(+6)

Question 17

Write the net ionic equation for the reaction of lead(II) nitrate and sodium iodide.

Accepted Answer

A)  Pb(NO3)2(aq) + 2NaI(aq) → PbI2(s) + 2 NaNO3(aq) 
B)  Pb2+ + 2 NaI(aq) → PbI2(s) + 2 Na 
C)  Pb2+ + 2 I- → PbI2(s) 
D)  Pb2+ + 2 I- → Pb2+ + 2 I- 
E)  no reaction 
A)  Pb(NO3)2(aq) + 2NaI(aq) → PbI2(s) + 2 NaNO3(aq) 
B)  Pb2+ + 2 NaI(aq) → PbI2(s) + 2 Na 
C)  Pb2+ + 2 I- → PbI2(s) 
D)  Pb2+ + 2 I- → Pb2+ + 2 I- 
E)  no reaction

Question 18

A 5.000 mL aqueous sample containing hydrogen peroxide was diluted to 25 mL and analyzed by titration with permanganate: 2MnO4- + 5H2O2 + 6H+ → 5O2 + 2Mn2+ + 8H2O
The sample required 42.8 mL of 0.0175 M permanganate to reach the end point. What is the concentration of hydrogen peroxide in the original sample?

Accepted Answer

A)  0.150 M 
B)  0.0748 M 
C)  0.374 M 
D)  0.0599 M 
A)  0.150 M 
B)  0.0748 M 
C)  0.374 M 
D)  0.0599 M

Question 19

A piece of iron wire weighing 1.63 g is converted to Fe2+(aq) and requires 21.9 mL of KMnO4 solution for its titration. What is the molarity of the KMnO4 solution? The reaction occurring during the titration is: 5 Fe2+ (aq) + MnO4- (aq) + 8 H+ (aq) → 5 Fe3+ (aq) + Mn2+ (aq) + 4 H2O

Accepted Answer

A)  1.33 M 
B)  0.267 M 
C)  2.67 × 10-4 M 
D)  14.9 M 
E)  1.33 × 10-3 M 
A)  1.33 M 
B)  0.267 M 
C)  2.67 × 10-4 M 
D)  14.9 M 
E)  1.33 × 10-3 M

Question 20

The analysis for iron usually is done by titration with permanganate. Identify the oxidizing agent in the following equation: MnO4- (aq) + 5 Fe2+ (aq) + 8 H+ → 5 Fe3+ (aq) + Mn2+ (aq) + 4 H2O

Accepted Answer

A)  MnO4- 
B)  Fe2+ 
C)  H+ 
D)  Mn2+ 
E)  It is not a redox reaction. 
A)  MnO4- 
B)  Fe2+ 
C)  H+ 
D)  Mn2+ 
E)  It is not a redox reaction.

Exam 5: Introduction to Reactions in Aqueous Solutions

Which of the following combinations is correct?

Gold does not react with either nitric acid or hydrochloric acid but with a combination of both called aqua regia. Identify the oxidizing agent in the following equation: Au(s) + 4 H+ + NO3- + 4 Cl- → [AuCl4]- + 2 H2O + NO(g)

A 0.411 g sample of powdered copper mixed with an inert, soluble additive was fully consumed by 23.4 mL of 0.602 M nitric acid, producing copper(II) nitrate, water, and nitric oxide (NO) gas. What was the percent copper (by mass) in the sample? 3 Cu + 8 HNO3 → 3 Cu(NO3)2 + 2 NO + 4 H2O

Which of the following is probably the poorest electrical conductor?

Balance the following equation in basic solution: Cr3+ + O22- → CrO42- The sum of the coefficients is ________.

For redox reactions to be balanced, electrons should be present on the reactant side.

Which of the following pairs of aqueous solutions will give a precipitate when mixed?

Complete the equation and indicate if a precipitate forms. Na+ + Cl- + NO3- + K+ →

Assuming that the proposed reactants are mixed in stoichiometric ratios, and at moderate concentrations, which of the following is least likely to represent an observable (e.g., gas evolution or precipitation) reaction?

In which of the following pairs is the oxidation number for the underlined element INCORRECT?

Balance the following equation in basic solution: Br2 + Mn2+ → MnO2 + Br- The sum of the coefficients is ________.

Which of the following would have the strongest tendency of producing OH- ions in an aqueous solution?

The substance CH3COOH in water is a:

Balance the following equation for an oxidation-reduction reaction occurring in an acidic solution: HNO3 + I2 → HIO3 + NO2 + H2O The sum of the coefficients is ________.

Which of the following compounds is quite insoluble in water, but would liberate a gas when treated with aqueous acetic acid?

In which of the following pairs is the oxidation number for the underlined element INCORRECT?

Write the net ionic equation for the reaction of lead(II) nitrate and sodium iodide.

A piece of iron wire weighing 1.63 g is converted to Fe2+(aq) and requires 21.9 mL of KMnO4 solution for its titration. What is the molarity of the KMnO4 solution? The reaction occurring during the titration is: 5 Fe2+ (aq) + MnO4- (aq) + 8 H+ (aq) → 5 Fe3+ (aq) + Mn2+ (aq) + 4 H2O

The analysis for iron usually is done by titration with permanganate. Identify the oxidizing agent in the following equation: MnO4- (aq) + 5 Fe2+ (aq) + 8 H+ → 5 Fe3+ (aq) + Mn2+ (aq) + 4 H2O

Matter - Its Properties and Measurement

Atoms and the Atomic Theory

Chemical Compounds

Chemical Reactions

Gases

Thermochemistry

Electrons in Atoms

The Periodic Table and Some Atomic Properties

Chemical Bonding I: Basic Concepts

Chemical Bonding II: Additional Aspects

Intermolecular Forces: Liquids and Solids

Solutions and Their Physical Properties

Chemical Kinetics

Principles of Chemical Equilibrium

Acids and Bases

Additional Aspects of Acid-Base Equilibria

Solubility and Complex-Ion Equilibria

Spontaneous Change: Entropy and Free Energy

Electrochemistry

Main Group Elements I: Groups 1, 2, 13, and 14

Main Group Elements II: Groups 18, 17, 16, 15, and Hydrogen

The Transition Elements

Complex Ions and Coordination Compounds

Nuclear Chemistry 1-41

Structures of Organic Compounds

Reactions of Organic Compounds

Chemistry of the Living State

Filters

Gold does not react with either nitric acid or hydrochloric acid but with a combination of both called aqua regia. Identify the oxidizing agent in the following equation: Au(s) + 4 H⁺ + NO₃^- + 4 Cl- → [AuCl₄]^- + 2 H₂O + NO(g)

A 0.411 g sample of powdered copper mixed with an inert, soluble additive was fully consumed by 23.4 mL of 0.602 M nitric acid, producing copper(II) nitrate, water, and nitric oxide (NO) gas. What was the percent copper (by mass) in the sample? 3 Cu + 8 HNO₃ → 3 Cu(NO₃)₂ + 2 NO + 4 H₂O

Balance the following equation in basic solution: Cr₃⁺ + O₂^2- → CrO₄^2- The sum of the coefficients is ________.

Complete the equation and indicate if a precipitate forms. Na⁺ + Cl^- + NO₃^- + K⁺ →

Balance the following equation in basic solution: Br₂ + Mn²⁺ → MnO₂ + Br- The sum of the coefficients is ________.

The substance CH₃COOH in water is a:

Balance the following equation for an oxidation-reduction reaction occurring in an acidic solution: HNO₃ + I₂ → HIO₃ + NO₂ + H₂O The sum of the coefficients is ________.

The analysis for iron usually is done by titration with permanganate. Identify the oxidizing agent in the following equation: MnO₄^- (aq) + 5 Fe²⁺ (aq) + 8 H⁺ → 5 Fe³⁺ (aq) + Mn²⁺ (aq) + 4 H₂O