AP Chemistry Practice Quiz: Galvanic (Voltaic) and Electrolytic Cells
Written by AP Content Team, Verified for 2026 AP Exams, Last updated: May 2026
Test your understanding with short quizzes. This quiz has 10 questions to check your progress.
Question 1 of 10
All Questions (10)
A) Oxidation occurs at the anode in galvanic cells, but at the cathode in electrolytic cells.
B) A galvanic cell is driven by a thermodynamically favored reaction, while an electrolytic cell drives a thermodynamically unfavored reaction.
C) Galvanic cells require an external power source, while electrolytic cells spontaneously generate an electric current.
D) The salt bridge is a necessary component for electrolytic cells but is optional for galvanic cells.
Correct Answer: B
The core distinction between the two cell types is based on thermodynamics. Galvanic (voltaic) cells harness a thermodynamically favored (spontaneous) reaction to produce electrical energy. In contrast, electrolytic cells use external electrical energy to force a thermodynamically unfavored (non-spontaneous) reaction to occur.
A) Reduction
B) Oxidation
C) Electron gain
D) Plating of solid metal
Correct Answer: B
A fundamental rule for all electrochemical cells is that oxidation, the loss of electrons, always takes place at the electrode defined as the anode. The mnemonic 'An Ox' (Anode-Oxidation) is a helpful reminder.
A) To allow electrons to flow directly between the half-cells.
B) To provide a surface for the oxidation and reduction half-reactions.
C) To maintain charge neutrality in the half-cells by allowing the migration of ions.
D) To mix the solutions of the two half-cells, allowing the reactants to interact directly.
Correct Answer: C
As a galvanic cell operates, ions are produced or consumed in each half-cell, which would lead to a buildup of charge. The salt bridge contains spectator ions that migrate into the half-cells to balance this charge, allowing the reaction and electron flow to continue.
A) The mass of the electrode will increase.
B) The mass of the electrode will decrease.
C) The mass of the electrode will remain unchanged.
D) The electrode will dissolve into the half-cell solution.
Correct Answer: A
The cathode is the site of reduction. In a typical galvanic cell with a metal electrode, reduction involves metal cations from the solution gaining electrons and depositing as solid metal onto the electrode's surface. This process causes the mass of the cathode to increase.
A) From the cathode to the anode through the external wire.
B) From the anode to the cathode through the salt bridge.
C) From the anode to the cathode through the external wire.
D) From the cathode to the anode through the half-cell solutions.
Correct Answer: C
Oxidation occurs at the anode, which means electrons are released at this electrode. These electrons then travel through the external circuit (the wire) to the cathode, where they are consumed during the reduction process. This direction of flow is consistent for both galvanic and electrolytic cells.
A) Electrode B is the anode, and the reaction is thermodynamically unfavored.
B) Electrode A is the cathode, and reduction is occurring there.
C) Electrode A is the anode, and oxidation is occurring there.
D) Electrode B is the anode, and oxidation is occurring there.
Correct Answer: C
Electrons are products of oxidation, which occurs at the anode. Since electrons are flowing away from Electrode A, it must be the anode where oxidation is taking place. Consequently, Electrode B is the cathode, the site of reduction. As it is a galvanic cell, the overall reaction is thermodynamically favored.
A) Cations from the solution are gaining electrons and depositing onto the anode.
B) Atoms from the solid anode are losing electrons and entering the solution as ions.
C) Anions from the salt bridge are reacting with the surface of the anode.
D) The anode is a catalyst and is not consumed in the reaction.
Correct Answer: B
The anode is the site of oxidation. A decrease in the mass of a reactive metal anode indicates that the electrode itself is being oxidized. At the particulate level, this means that neutral atoms composing the solid electrode lose one or more electrons and become positively charged ions that dissolve into the solution.
A) Anode: Site of reduction.
B) Cathode: Site of oxidation.
C) Anode: Site of electron gain.
D) Cathode: Site of reduction.
Correct Answer: D
By definition, the cathode is the electrode where reduction (the gain of electrons) occurs, and the anode is the electrode where oxidation (the loss of electrons) occurs. This is true for both galvanic and electrolytic cells. The mnemonic 'Red Cat' (Reduction at the Cathode) is a useful tool.
A) The spoon is the anode, and it is the site of a reduction reaction.
B) The spoon is the cathode, and it is the site of an oxidation reaction.
C) The spoon is the cathode, and it is the site of a reduction reaction.
D) The reaction is thermodynamically favored and occurs spontaneously.
Correct Answer: C
Electroplating is a reduction process (Ag⁺ + e⁻ → Ag(s)). Reduction always occurs at the cathode. Therefore, the object to be plated, the spoon, must be the cathode. Since this is an electrolytic cell, the process is thermodynamically unfavored and requires an external power source.
A) It converts electrical energy into chemical energy via a thermodynamically unfavored reaction.
B) Electrons flow from the cathode to the anode, and ions flow through the external wire.
C) It converts chemical energy into electrical energy via a thermodynamically favored reaction.
D) Oxidation occurs at the cathode, and reduction occurs at the anode.
Correct Answer: C
A galvanic cell is defined by its ability to generate electrical energy from a stored chemical potential. This is achieved through a thermodynamically favored (spontaneous) redox reaction. The other options are incorrect: A describes an electrolytic cell, B reverses electron flow and misidentifies the role of the wire, and D reverses the locations of oxidation and reduction.