Chapter 16: Electrochemistry

Question 1

What occurs at the anode in a galvanic cell?
A) Reduction
B) Oxidation
C) Precipitation
D) Decomposition

Answer 1

B) Oxidation

Question 2

What is the general format of cell notation?
A) Cathode || Anode
B) Anode || Cathode
C) Anode | Anode solution || Cathode solution | Cathode
D) Anode | Cathode solution | Cathode

Answer 2

C) Anode | Anode solution || Cathode solution | Cathode

Question 3

What is a redox reaction?
A) A reaction where electrons are shared
B) A reaction where both products are gases
C) A reaction where one species is oxidized and another is reduced
D) A double-replacement reaction

Answer 3

C) A reaction where one species is oxidized and another is reduced

Question 4

What does a positive E°cell mean?
A) The reaction is at equilibrium
B) The redox reaction is spontaneous under standard conditions
C) The anode is gaining electrons
D) The solution is acidic

Answer 4

B) The redox reaction is spontaneous under standard conditions

Question 5

What occurs at the cathode in a galvanic cell?
A) Oxidation
B) Reduction
C) Electrolysis
D) Precipitation

Answer 5

B) Reduction

Question 6

What is electrolysis?
A) A spontaneous redox reaction
B) The movement of ions in salt bridges
C) The use of electricity to drive a non-spontaneous reaction
D) A process where heat drives a reaction

Answer 6

C) The use of electricity to drive a non-spontaneous reaction

Question 7

What is a fuel cell?
A) A battery that recharges by heat
B) A cell that stores potential energy as light
C) A device that converts chemical energy into electricity using a redox reaction
D) A cell that requires combustion to work

Answer 7

C) A device that converts chemical energy into electricity using a redox reaction

Question 8

In the cell notation Cu(s) | Cu²⁺ || Ag⁺ | Ag(s), which electrode is oxidized?
A) Ag
B) Cu
C) Ag⁺
D) Cu²⁺

Answer 8

B) Cu

Question 9

What does Q represent in the Nernst equation?
A) The number of moles of electrons
B) The total charge of the cell
C) The reaction quotient based on concentrations
D) The heat of the system

Answer 9

C) The reaction quotient based on concentrations

Question 10

How is the equilibrium constant K related to E°cell?
A) E°cell = -nF/RT
B) E°cell = (RT/nF) lnK
C) K = nFE°
D) K = -nFE°

Answer 10

B) E°cell = (RT/nF) lnK

Question 11

How do you balance oxygen atoms in a redox reaction?
A) Add H⁺
B) Add electrons
C) Add H₂O to the side with fewer O atoms
D) Add OH⁻

Answer 11

C) Add H₂O to the side with fewer O atoms

Question 12

How do you balance hydrogen atoms in acidic solutions?
A) Add H₂ gas
B) Add OH⁻
C) Add H⁺ ions
D) Subtract water

Answer 12

C) Add H⁺ ions

Question 13

What do you add to balance charges in redox half-reactions?
A) OH⁻
B) Water
C) Electrons
D) H⁺

Answer 13

C) Electrons

Question 14

What’s the last step in balancing a redox reaction?
A) Multiply both half-reactions by coefficients
B) Add the reactions and cancel out common species
C) Add H₂O
D) Add OH⁻

Answer 14

B) Add the reactions and cancel out common species

Question 15

How do you balance a redox reaction in basic solution?
A) Add OH⁻ to both sides to neutralize H⁺
B) Remove water
C) Ignore the H⁺
D) Double the coefficients

Answer 15

A) Add OH⁻ to both sides to neutralize H⁺

Question 16

Which of the following species is being reduced in the reaction: Zn + Cu²⁺ → Zn²⁺ + Cu?
A) Zn
B) Cu²⁺
C) Cu
D) Zn²⁺

Answer 16

B) Cu²⁺

Question 17

Which electrode in a galvanic cell loses mass over time?
A) Cathode
B) Salt bridge
C) Anode
D) Both electrodes

Answer 17

C) Anode

Question 18

What is the purpose of the salt bridge in a galvanic cell?
A) To produce current
B) To provide a source of electrons
C) To prevent precipitation
D) To maintain electrical neutrality by allowing ion flow

Answer 18

D) To maintain electrical neutrality by allowing ion flow

Question 19

Which of the following is true for a spontaneous redox reaction?
A) ΔG > 0 and E°cell < 0
B) ΔG < 0 and E°cell > 0
C) ΔG = 0 and E°cell = 0
D) ΔG > 0 and E°cell > 0

Answer 19

B) ΔG < 0 and E°cell > 0

Question 20

What is the reducing agent in a redox reaction?
A) The substance that is reduced
B) The substance that gains electrons
C) The substance that causes oxidation and is itself oxidized
D) The substance that forms a salt bridge

Answer 20

C) The substance that causes oxidation and is itself oxidized

Question 21

What does a negative standard cell potential (E°cell) indicate?
A) The reaction is spontaneous
B) Electrons are gained at the anode
C) The reaction is non-spontaneous
D) The salt bridge is broken

Answer 21

C) The reaction is non-spontaneous

Question 22

In the half-reaction MnO₄⁻ + 8H⁺ + 5e⁻ → Mn²⁺ + 4H₂O, what is being reduced?
A) H⁺
B) MnO₄⁻
C) Mn²⁺
D) H₂O

Answer 22

B) MnO₄⁻

Question 23

Identify the reactant that gets oxidized in the following reaction.

2 AgNO₃(aq) + CaI₂(aq) → 2 AgI(s) + Ca(NO₃)₂(aq)

a. Ag
b. I
c. N
d. Ca
e. not a redox reaction

Answer 23

e. not a redox reaction

Question 24

Identify the reactant that gets reduced in the following reaction.

3ReO₄⁻(aq) + 7MnO₂(s) + 2H₂O(l) → 3Re(s) + 7MnO₄⁻(aq) + 4H⁺(aq)

a.) Re in ReO4-
b.) Mn in MnO2
c.) Re in Re(s)
d.) Mn in MnO4-
e.) this is not a redox reaction

Answer 24

a.) Re in ReO4-

Question 25

How many electrons are exchanged in the following reaction? 2 Fe³⁺(aq) + 3 Cu(s) ⇌ 2 Fe(s) + 3 Cu²⁺(aq)

Answer 25

6

Question 26

What is the smallest whole-number coefficient for H₂O when the equation MnO₄⁻ + I⁻ + H₂O → MnO₂ + IO₃⁻ is balanced in basic solution?