Question 1

Which of these metals will reduce water to hydrogen in basic solution under standard conditions?

Accepted Answer

A) Pb 
B) Fe 
C) Zn 
D) Na 
E) Ag 
A) Pb 
B) Fe 
C) Zn 
D) Na 
E) Ag

Question 2

Will H2(g)form when Fe is placed in 1.0 M HCl?

Accepted Answer

Question 3

Calculate the cell emf for the following reaction at 25°C:
2Ag+(0.010 M)+ H2(1 atm)$\rarr$ 2Ag(s)+ 2H+(pH = 6.0)

Accepted Answer

The answer of Calculate the cell emf for the following...

Question 4

Using a table of standard reduction potentials, determine which of these reactions (if any)is/are nonspontaneous in the direction indicated at 25°C.

Accepted Answer

A) 2Fe3+ + 2Cl- $\rarr$ 2Fe2+ + Cl2(g) 
B) 2Fe3+ + 2Br- $\rarr$ 2Fe2+ + Br2(l) 
C) 2Fe3+ + 2I- $\rarr$ 2Fe2+ + I2(s) 
D) A and B 
E) All are spontaneous. 
A) 2Fe3+ + 2Cl- $\rarr$ 2Fe2+ + Cl2(g) 
B) 2Fe3+ + 2Br- $\rarr$ 2Fe2+ + Br2(l) 
C) 2Fe3+ + 2I- $\rarr$ 2Fe2+ + I2(s) 
D) A and B 
E) All are spontaneous.

Question 5

Determine the equilibrium constant (Keq)at 25°C for the reaction Cl2(g)+ 2Br- (aq)$\rarr$ 2Cl- (aq)+ Br2(l)

Accepted Answer

A) 1.5 * 10-10 
B) 6.3 * 109 
C) 1.3 * 1041 
D) 8.1 * 104 
E) 9.8 
A) 1.5 * 10-10 
B) 6.3 * 109 
C) 1.3 * 1041 
D) 8.1 * 104 
E) 9.8

Question 6

Complete and balance the following redox equation using the set of smallest whole-numbers coefficients. What is the sum of the coefficients? 
HI + HNO3 $\rarr$ I2 + NO (acidic solution)

Accepted Answer

A) 5 
B) 7 
C) 14 
D) 17 
E) None of these. 
A) 5 
B) 7 
C) 14 
D) 17 
E) None of these.

Question 7

Given the following notation for an electrochemical cell Pt(s)| H2(g)| H+(aq)|| Ag+(aq)| Ag(s)
What is the balanced overall (net)cell reaction?

Accepted Answer

A) 2H+(aq)+ 2Ag+(aq)$\rarr$H2(g)+ 2Ag(s) 
B) H2(g)+ 2Ag(s)$\rarr$ H+(aq)+ 2Ag+(aq) 
C) 2H+(aq)+ 2Ag(s)$\rarr$ H2(g)+ 2Ag+(aq) 
D) H2(g)+ Ag+(aq)$\rarr$ H+(aq)+ Ag(s) 
E) H2(g)+ 2Ag+(aq)$\rarr$2H+(aq)+ 2Ag(s) 
A) 2H+(aq)+ 2Ag+(aq)$\rarr$H2(g)+ 2Ag(s) 
B) H2(g)+ 2Ag(s)$\rarr$ H+(aq)+ 2Ag+(aq) 
C) 2H+(aq)+ 2Ag(s)$\rarr$ H2(g)+ 2Ag+(aq) 
D) H2(g)+ Ag+(aq)$\rarr$ H+(aq)+ Ag(s) 
E) H2(g)+ 2Ag+(aq)$\rarr$2H+(aq)+ 2Ag(s)

Question 8

For the electrochemical cell Ni(s)| Ni2+(1 M)|| H+(1 M)| H2(1 atm)| Pt(s), which one of the following changes will cause a decrease in the cell voltage?

Accepted Answer

A) Increase the pressure of H2 to 2.0 atm. 
B) Decrease the mass of the nickel electrode. 
C) Lower the pH of the cell electrolyte. 
D) Decrease the concentration of Ni2+ ion. 
E) None of the above. 
A) Increase the pressure of H2 to 2.0 atm. 
B) Decrease the mass of the nickel electrode. 
C) Lower the pH of the cell electrolyte. 
D) Decrease the concentration of Ni2+ ion. 
E) None of the above.

Question 9

Consider the following standard reduction potentials in acid solution:   Which is the weakest oxidizing agent in this list?

Accepted Answer

A) Al3+(aq) 
B) Al(s) 
C) I-(aq) 
D) I2(s) 
E) Sn4+(aq) 
A) Al3+(aq) 
B) Al(s) 
C) I-(aq) 
D) I2(s) 
E) Sn4+(aq)

Question 10

Calculate the minimum voltage required for the electrolysis of 1.0 M NaCl in neutral solution. 2H2O + 2Cl- (1.0 M)$\rarr$ H2(1 atm)+ Cl2(1 atm)+ 2OH- (1 * 10-7 M)

Accepted Answer

A) 2.19 V 
B) 1.78 V 
C) 0.41 V 
D) -0.41 V 
E) -1.78 V 
A) 2.19 V 
B) 1.78 V 
C) 0.41 V 
D) -0.41 V 
E) -1.78 V

Question 11

Given the following standard reduction potentials in acid solution
O2 + 4H+ + 4e- $\rarr$ 2H2O E° = +1.23 V
Sn4+ + 2e- $\rarr$ Sn2+ E° = +0.13 V
Zn2+ + 2e- $\rarr$ Zn(s)E° = -0.76 V
write the formula of the strongest oxidizing agent.

Accepted Answer

The answer of Given the following standard reduction potentials in...

Question 12

A certain electrochemical cell has for its cell reaction: Zn + HgO $\rarr$ ZnO + Hg
Which is the half-reaction occurring at the anode?

Accepted Answer

A) HgO + 2e- $\rarr$ Hg + O2- 
B) Zn2+ + 2e- $\rarr$ Zn 
C) Zn $\rarr$ Zn2+ + 2e- 
D) ZnO + 2e- $\rarr$ Zn 
A) HgO + 2e- $\rarr$ Hg + O2- 
B) Zn2+ + 2e- $\rarr$ Zn 
C) Zn $\rarr$ Zn2+ + 2e- 
D) ZnO + 2e- $\rarr$ Zn

Question 13

When a solution of a certain gadolinium salt is electrolyzed with a current of 1.0 A for 2.0 h, 0.025 mol of Gd metal forms. Calculate the charge on the gadolinium ion in the salt.

Accepted Answer

The answer of When a solution of a certain gadolinium...

Question 14

Which one of the following reagents is capable of transforming Br- (aq)to Br2(l)under standard-state conditions?

Accepted Answer

A) I- (aq) 
B) NO3- (aq) 
C) Ag+ (aq) 
D) Al3+ (aq) 
E) Au3+ (aq) 
A) I- (aq) 
B) NO3- (aq) 
C) Ag+ (aq) 
D) Al3+ (aq) 
E) Au3+ (aq)

Question 15

The overall reaction 2Co3+(aq)+ 2Cl-(aq)$\rarr$ 2Co2+(aq)+ Cl2(g)has the standard cell voltage E°cell = 0.46 V. Given E° = 1.36 V for the reaction Cl2(g)+ 2e- $\rarr$ 2Cl-(aq), calculate the standard reduction potential for the following the half reaction at 25°C: Co3+ + e- $\rarr$ Co2+

Accepted Answer

A) 1.82 V 
B) -0.90 V 
C) 0.90 V 
D) -1.82 V 
E) -1.36 V 
A) 1.82 V 
B) -0.90 V 
C) 0.90 V 
D) -1.82 V 
E) -1.36 V

Question 16

Which of these metals will not reduce water to hydrogen in basic solution under standard conditions?

Accepted Answer

A) Cd 
B) Sr 
C) Mg 
D) Ba 
E) K 
A) Cd 
B) Sr 
C) Mg 
D) Ba 
E) K

Question 17

Consider an electrochemical cell with the following cell reaction where all reactants and products are at standard-state conditions: Cu2+(aq)+ H2(g)$\rarr$ Cu(s)+ 2H+(aq). Predict the effect on the emf of this cell of adding NaOH solution to the hydrogen half-cell until the pH equals 7.0.

Accepted Answer

A) The emf will increase. 
B) The emf will decrease. 
C) No change in the emf will be observed. 
A) The emf will increase. 
B) The emf will decrease. 
C) No change in the emf will be observed.

Question 18

Determine the equilibrium constant, Keq, at 25°C for the reaction 2Br- (aq)+ I2(s)$\rarr$Br2(l)+ 2I- (aq)

Accepted Answer

A) 5.7 * 10-19 
B) 18.30 
C) 1.7 * 1054 
D) 1.9 * 1018 
E) 5.7 * 10-55 
A) 5.7 * 10-19 
B) 18.30 
C) 1.7 * 1054 
D) 1.9 * 1018 
E) 5.7 * 10-55

Question 19

Consider an electrochemical cell based on the spontaneous reaction 2AgCl(s)+ Zn(s)$\rarr$ 2Ag(s)+ 2Cl-  + Zn2+.
If the zinc ion concentration is kept constant at 1 M, and the chlorine ion concentration is decreased from 1 M to 0.001 M, the cell voltage should

Accepted Answer

A) increase by 0.06 V. 
B) increase by 0.18 V. 
C) decrease by 0.06 V. 
D) decrease by 0.18 V. 
E) increase by 0.35 V. 
A) increase by 0.06 V. 
B) increase by 0.18 V. 
C) decrease by 0.06 V. 
D) decrease by 0.18 V. 
E) increase by 0.35 V.

Question 20

Complete and balance the following redox equation. What is the coefficient of H2O when the equation is balanced using the set of smallest whole-number coefficients? MnO4- + SO32- $\rarr$ Mn2+ + SO42-  (acidic solution)

Accepted Answer

A) 3 
B) 4 
C) 5 
D) 8 
E) None of these. 
A) 3 
B) 4 
C) 5 
D) 8 
E) None of these.

Exam 19: Redox Reactions and Electrochemistry

Which of these metals will reduce water to hydrogen in basic solution under standard conditions?

Will H2(g)form when Fe is placed in 1.0 M HCl?

Calculate the cell emf for the following reaction at 25°C: 2Ag+(0.010 M)+ H2(1 atm) →\rarr→ 2Ag(s)+ 2H+(pH = 6.0)

Using a table of standard reduction potentials, determine which of these reactions (if any)is/are nonspontaneous in the direction indicated at 25°C.

Determine the equilibrium constant (Keq)at 25°C for the reaction Cl2(g)+ 2Br- (aq) →\rarr→ 2Cl- (aq)+ Br2(l)

Complete and balance the following redox equation using the set of smallest whole-numbers coefficients. What is the sum of the coefficients? HI + HNO3 →\rarr→ I2 + NO (acidic solution)

Given the following notation for an electrochemical cell Pt(s)| H2(g)| H+(aq)|| Ag+(aq)| Ag(s) What is the balanced overall (net)cell reaction?

For the electrochemical cell Ni(s)| Ni2+(1 M)|| H+(1 M)| H2(1 atm)| Pt(s), which one of the following changes will cause a decrease in the cell voltage?

Consider the following standard reduction potentials in acid solution: Which is the weakest oxidizing agent in this list?

Calculate the minimum voltage required for the electrolysis of 1.0 M NaCl in neutral solution. 2H2O + 2Cl- (1.0 M) →\rarr→ H2(1 atm)+ Cl2(1 atm)+ 2OH- (1 * 10-7 M)

Given the following standard reduction potentials in acid solution O2 + 4H+ + 4e- →\rarr→ 2H2O E° = +1.23 V Sn4+ + 2e- →\rarr→ Sn2+ E° = +0.13 V Zn2+ + 2e- →\rarr→ Zn(s)E° = -0.76 V write the formula of the strongest oxidizing agent.

A certain electrochemical cell has for its cell reaction: Zn + HgO →\rarr→ ZnO + Hg Which is the half-reaction occurring at the anode?

When a solution of a certain gadolinium salt is electrolyzed with a current of 1.0 A for 2.0 h, 0.025 mol of Gd metal forms. Calculate the charge on the gadolinium ion in the salt.

Which one of the following reagents is capable of transforming Br- (aq)to Br2(l)under standard-state conditions?

Which of these metals will not reduce water to hydrogen in basic solution under standard conditions?

Consider an electrochemical cell with the following cell reaction where all reactants and products are at standard-state conditions: Cu2+(aq)+ H2(g) →\rarr→ Cu(s)+ 2H+(aq). Predict the effect on the emf of this cell of adding NaOH solution to the hydrogen half-cell until the pH equals 7.0.

Determine the equilibrium constant, Keq, at 25°C for the reaction 2Br- (aq)+ I2(s) →\rarr→ Br2(l)+ 2I- (aq)

Consider an electrochemical cell based on the spontaneous reaction 2AgCl(s)+ Zn(s) →\rarr→ 2Ag(s)+ 2Cl- + Zn2+. If the zinc ion concentration is kept constant at 1 M, and the chlorine ion concentration is decreased from 1 M to 0.001 M, the cell voltage should

Complete and balance the following redox equation. What is the coefficient of H2O when the equation is balanced using the set of smallest whole-number coefficients? MnO4- + SO32- →\rarr→ Mn2+ + SO42- (acidic solution)

Introduction

Atoms, Molecules, and Ions

Stoichiometry

Reactions in Aqueous Solution

Gases

Energy Relationships in Chemical Reactions

The Electronic Structure of Atoms

The Periodic Table

Chemical Bonding I: the Covalent Bond

Chemical Bonding Ii: Molecular Geometry and Hybridization of Atomic Orbitals

Introduction to Organic Chemistry

Intermolecular Forces and Liquids and Solids

Physical Properties of Solutions

Chemical Kinetics

Chemical Equilibrium

Acids and Bases

Acid-Base Equilibria and Solubility Equilibria

Thermodynamics

The Chemistry of Coordination Compounds

Nuclear Chemistry

Organic Polymerssynthetic and Natural

Filters

Will H₂(g)form when Fe is placed in 1.0 M HCl?

Calculate the cell emf for the following reaction at 25°C: 2Ag⁺(0.010 M)+ H₂(1 atm) $\rarr$ 2Ag(s)+ 2H⁺(pH = 6.0)

Determine the equilibrium constant (K_eq)at 25°C for the reaction Cl₂(g)+ 2Br^-(aq) $\rarr$ 2Cl^-(aq)+ Br₂(l)

Complete and balance the following redox equation using the set of smallest whole-numbers coefficients. What is the sum of the coefficients? HI + HNO₃ $\rarr$ I₂ + NO (acidic solution)

Given the following notation for an electrochemical cell Pt(s)| H₂(g)| H⁺(aq)|| Ag⁺(aq)| Ag(s) What is the balanced overall (net)cell reaction?

For the electrochemical cell Ni(s)| Ni²⁺(1 M)|| H⁺(1 M)| H₂(1 atm)| Pt(s), which one of the following changes will cause a decrease in the cell voltage?

Calculate the minimum voltage required for the electrolysis of 1.0 M NaCl in neutral solution. 2H₂O + 2Cl^-(1.0 M) $\rarr$ H₂(1 atm)+ Cl₂(1 atm)+ 2OH^-(1 * 10^-7 M)

Given the following standard reduction potentials in acid solution O₂ + 4H⁺ + 4e^- $\rarr$ 2H₂O E° = +1.23 V Sn⁴⁺ + 2e^- $\rarr$ Sn²⁺E° = +0.13 V Zn²⁺ + 2e^- $\rarr$ Zn(s)E° = -0.76 V write the formula of the strongest oxidizing agent.

A certain electrochemical cell has for its cell reaction: Zn + HgO $\rarr$ ZnO + Hg Which is the half-reaction occurring at the anode?

Which one of the following reagents is capable of transforming Br^-(aq)to Br₂(l)under standard-state conditions?

Consider an electrochemical cell with the following cell reaction where all reactants and products are at standard-state conditions: Cu²⁺(aq)+ H₂(g) $\rarr$ Cu(s)+ 2H⁺(aq). Predict the effect on the emf of this cell of adding NaOH solution to the hydrogen half-cell until the pH equals 7.0.

Determine the equilibrium constant, K_eq, at 25°C for the reaction 2Br^-(aq)+ I₂(s) $\rarr$ Br₂(l)+ 2I^-(aq)

Consider an electrochemical cell based on the spontaneous reaction 2AgCl(s)+ Zn(s) $\rarr$ 2Ag(s)+ 2Cl^- + Zn²⁺. If the zinc ion concentration is kept constant at 1 M, and the chlorine ion concentration is decreased from 1 M to 0.001 M, the cell voltage should

Complete and balance the following redox equation. What is the coefficient of H₂O when the equation is balanced using the set of smallest whole-number coefficients? MnO₄^- + SO₃^2- $\rarr$ Mn²⁺ + SO₄^2- (acidic solution)