CHEM134 C003 Lesson 7 Quiz | Questions and
Answers – spring 2026 | 100% Correct - American
Public University.
SECTION 1: VOLTAIC CELLS & ELECTROCHEMICAL FUNDAMENTALS
Question 1
Which of the following statements correctly describes the function of the salt
bridge in a voltaic cell?
A. It acts as a resistor to slow down the reaction.
B. It provides a pathway for the migration of ions to maintain electrical
neutrality in the half-cells.
C. It is the site where oxidation occurs.
D. It provides a direct flow of electrons between the two half-cells.
Correct Answer: B
Rationale: As the cell operates, the anode half-cell accumulates positive ions
(cations) from oxidation, and the cathode half-cell becomes depleted of them. The
salt bridge contains inert ions that migrate into the half-cells to neutralize these
changes, preventing the buildup of charge that would stop the reaction .
Question 2
In a voltaic cell, the half-cell where reduction occurs is called the:
A. Anode
B. Cathode
C. Salt bridge
D. External circuit
Correct Answer: B
,Rationale: Reduction always takes place at the cathode. Oxidation occurs at the
anode. A simple mnemonic is "Red Cat" (reduction at cathode) and "An Ox"
(oxidation at anode).
Question 3
The electrons in a voltaic cell flow from:
A. The cathode to the anode through the salt bridge
B. The anode to the cathode through the external circuit
C. The cathode to the anode through the external circuit
D. The anode to the cathode through the salt bridge
Correct Answer: B
Rationale: In a voltaic cell, electrons flow from the anode (where oxidation occurs)
to the cathode (where reduction occurs) through the external circuit. This flow of
electrons is what generates an electric current.
Question 4
Which of the following is NOT a component of a typical voltaic cell?
A. Anode
B. Cathode
C. Salt bridge
D. A power source
Correct Answer: D
Rationale: A voltaic cell is a spontaneous electrochemical cell that generates its
own electrical energy from a chemical reaction. It does not require an external
power source; in fact, it is itself a power source. An external power source is used
in electrolytic cells .
, Question 5
Oxidation in an electrochemical cell occurs at the:
A. Anode
B. Cathode
C. Salt bridge
D. External circuit
Correct Answer: A
Rationale: Oxidation occurs at the anode. Remember: "An Ox" = Oxidation at
Anode. Reduction occurs at the cathode ("Red Cat").
SECTION 2: STANDARD REDUCTION POTENTIALS (Questions 6-20)
Question 6
Given the standard reduction potentials below, which species is the strongest
reducing agent?
Ag⁺ + e⁻ → Ag(s) E° = +0.80 V
Zn²⁺ + 2e⁻ → Zn(s) E° = -0.76 V
A. Ag⁺(aq)
B. Ag(s)
C. Zn²⁺(aq)
D. Zn(s)
Correct Answer: D
Rationale: A reducing agent is a species that loses electrons (is oxidized). The more
negative the reduction potential of a half-reaction, the greater the tendency of the
reactant to be oxidized. Therefore, Zn(s), with E° = -0.76 V, is a stronger reducing
agent than Ag(s).
Answers – spring 2026 | 100% Correct - American
Public University.
SECTION 1: VOLTAIC CELLS & ELECTROCHEMICAL FUNDAMENTALS
Question 1
Which of the following statements correctly describes the function of the salt
bridge in a voltaic cell?
A. It acts as a resistor to slow down the reaction.
B. It provides a pathway for the migration of ions to maintain electrical
neutrality in the half-cells.
C. It is the site where oxidation occurs.
D. It provides a direct flow of electrons between the two half-cells.
Correct Answer: B
Rationale: As the cell operates, the anode half-cell accumulates positive ions
(cations) from oxidation, and the cathode half-cell becomes depleted of them. The
salt bridge contains inert ions that migrate into the half-cells to neutralize these
changes, preventing the buildup of charge that would stop the reaction .
Question 2
In a voltaic cell, the half-cell where reduction occurs is called the:
A. Anode
B. Cathode
C. Salt bridge
D. External circuit
Correct Answer: B
,Rationale: Reduction always takes place at the cathode. Oxidation occurs at the
anode. A simple mnemonic is "Red Cat" (reduction at cathode) and "An Ox"
(oxidation at anode).
Question 3
The electrons in a voltaic cell flow from:
A. The cathode to the anode through the salt bridge
B. The anode to the cathode through the external circuit
C. The cathode to the anode through the external circuit
D. The anode to the cathode through the salt bridge
Correct Answer: B
Rationale: In a voltaic cell, electrons flow from the anode (where oxidation occurs)
to the cathode (where reduction occurs) through the external circuit. This flow of
electrons is what generates an electric current.
Question 4
Which of the following is NOT a component of a typical voltaic cell?
A. Anode
B. Cathode
C. Salt bridge
D. A power source
Correct Answer: D
Rationale: A voltaic cell is a spontaneous electrochemical cell that generates its
own electrical energy from a chemical reaction. It does not require an external
power source; in fact, it is itself a power source. An external power source is used
in electrolytic cells .
, Question 5
Oxidation in an electrochemical cell occurs at the:
A. Anode
B. Cathode
C. Salt bridge
D. External circuit
Correct Answer: A
Rationale: Oxidation occurs at the anode. Remember: "An Ox" = Oxidation at
Anode. Reduction occurs at the cathode ("Red Cat").
SECTION 2: STANDARD REDUCTION POTENTIALS (Questions 6-20)
Question 6
Given the standard reduction potentials below, which species is the strongest
reducing agent?
Ag⁺ + e⁻ → Ag(s) E° = +0.80 V
Zn²⁺ + 2e⁻ → Zn(s) E° = -0.76 V
A. Ag⁺(aq)
B. Ag(s)
C. Zn²⁺(aq)
D. Zn(s)
Correct Answer: D
Rationale: A reducing agent is a species that loses electrons (is oxidized). The more
negative the reduction potential of a half-reaction, the greater the tendency of the
reactant to be oxidized. Therefore, Zn(s), with E° = -0.76 V, is a stronger reducing
agent than Ag(s).
