• 55 questions

AP Chem Electrochemistry Practice Test

An unofficial AP Chemistry electrochemistry practice test for Unit 9: galvanic and electrolytic cells, cell potential and Faraday's law.

In every electrochemical cell, galvanic or electrolytic, which process takes place at the anode?

Pick an answer, then press Check answer. Then you see Correct or Not quite, with the reason. Keys: 1 to 4 pick, Enter checks.

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Unofficial practice questions, not affiliated with the College Board. Bank checked October 11, 2026.

Next step AP Chemistry equilibrium practice testMore electrochemistry: General Chemistry 2

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Topic 9.8: Galvanic (voltaic) and electrolytic cells 17

  • A galvanic cell has a zinc electrode in a Zn²⁺ solution and a copper electrode in a Cu²⁺ solution. Which way do electrons move through the wire? Purdue University, General Chemistry Topic Review, "Electrochemical Reactions"; course topic 9.8
  • A galvanic cell joins a zinc half-cell to a platinum wire that sits in 1 M HCl with H₂ gas bubbling over it. Bubbles of H₂ form on the platinum. What is the platinum wire? Purdue University, General Chemistry Topic Review, "Electrochemical Reactions"; course topic 9.8
  • A steel spoon is to be plated with silver in an electrolytic cell that holds a solution of silver ions. How should the spoon be connected? Wikipedia, "Electroplating"; course topic 9.8
  • A zinc-copper galvanic cell delivers current for an hour. What has happened to the two metal electrodes? Purdue University, General Chemistry Topic Review, "Electrochemical Reactions"; course topic 9.8
  • A zinc-copper galvanic cell has a salt bridge filled with KCl solution. As the cell runs, where do the Cl⁻ ions of the bridge go? Purdue University, General Chemistry Topic Review, "Electrochemical Reactions"; course topic 9.8
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Topic 9.8: Galvanic (voltaic) and electrolytic cells, continued

  • An electric current is passed through melted table salt, NaCl, between inert electrodes. Which product collects at the cathode? Purdue University, General Chemistry Topic Review, "Electrolytic Cells"; course topic 9.8
  • As a zinc-copper galvanic cell runs, what happens to the concentration of Cu²⁺ in the copper half-cell? Purdue University, General Chemistry Topic Review, "Electrochemical Reactions"; course topic 9.8
  • In an electrolytic cell, at which electrode does reduction take place? College Board, AP Chemistry Course and Exam Description, topic 9.8, essential knowledge 9.8.A.3
  • In every electrochemical cell, galvanic or electrolytic, which process takes place at the anode? College Board, AP Chemistry Course and Exam Description, topic 9.8, essential knowledge 9.8.A.3
  • Inside an electrochemical cell, toward which electrode do cations move? Purdue University, General Chemistry Topic Review, "Electrochemical Reactions"; course topic 9.8
  • Molten NaCl is electrolyzed. Which half-reaction takes place at the anode? Purdue University, General Chemistry Topic Review, "Electrolytic Cells"; course topic 9.8
  • The salt bridge is lifted out of a working galvanic cell. What happens? Purdue University, General Chemistry Topic Review, "Electrochemical Reactions"; course topic 9.8
  • Two half-cells are joined by a wire, and a tube of salt solution is then set between the two beakers to complete the cell. What does the tube do? Purdue University, General Chemistry Topic Review, "Electrochemical Reactions"; course topic 9.8
  • Water that holds a little dissolved Na₂SO₄ is electrolyzed with inert electrodes. Which gas collects at the cathode? Purdue University, General Chemistry Topic Review, "Electrolytic Cells"; course topic 9.8
  • When a solution of NaCl in water is electrolyzed, hydrogen gas forms at the cathode and sodium metal does not. Why? Purdue University, General Chemistry Topic Review, "Electrolytic Cells"; course topic 9.8
  • Which statement sets a galvanic cell apart from an electrolytic cell? College Board, AP Chemistry Course and Exam Description, topic 9.8, essential knowledge 9.8.A.2
  • Why is a salt such as Na₂SO₄ dissolved in water before the water is electrolyzed? Purdue University, General Chemistry Topic Review, "Electrolytic Cells"; course topic 9.8

Topic 9.9: Cell potential and free energy 15

  • A cell reaction has a positive E°. What is the sign of ΔG° for that reaction? College Board, AP Chemistry Course and Exam Description, topic 9.9, essential knowledge 9.9.A.3
  • A galvanic cell is made from a Ni²⁺/Ni half-cell (E° = −0.23 V) and an Ag⁺/Ag half-cell (E° = +0.80 V). Which one is the anode, and why? Purdue University, General Chemistry Topic Review, "Electrochemical Reactions"; course topic 9.9
  • A redox reaction has E° = −0.59 V as written. What does the sign tell you? College Board, AP Chemistry Course and Exam Description, topic 9.9, essential knowledge 9.9.A.1
  • For Zn + Cu²⁺ → Zn²⁺ + Cu, E° = +1.10 V. Using ΔG° = −nFE° with F = 96,485 C/mol, what is ΔG° to three significant figures? College Board, AP Chemistry Course and Exam Description, topic 9.9, essential knowledge 9.9.A.3
  • The reaction Cu + 2 H⁺ → Cu²⁺ + H₂ has E° = −0.34 V. What is E° for the reverse reaction, Cu²⁺ + H₂ → Cu + 2 H⁺? Purdue University, General Chemistry Topic Review, "Electrochemical Reactions"; course topic 9.9
  • Standard reduction potentials: Cu²⁺ + 2 e⁻ → Cu, +0.34 V; Ag⁺ + e⁻ → Ag, +0.80 V. What is E° for Cu + 2 Ag⁺ → Cu²⁺ + 2 Ag? Purdue University, General Chemistry Topic Review, "Electrochemical Reactions"; course topic 9.9
  • Standard reduction potentials: Fe³⁺ + e⁻ → Fe²⁺, +0.77 V; Cl₂ + 2 e⁻ → 2 Cl⁻, +1.36 V. What is true of 2 Fe³⁺ + 2 Cl⁻ → 2 Fe²⁺ + Cl₂? Purdue University, General Chemistry Topic Review, "Electrochemical Reactions"; course topic 9.9
  • Standard reduction potentials: Mg²⁺/Mg, −2.38 V; Zn²⁺/Zn, −0.76 V; Cu²⁺/Cu, +0.34 V; Ag⁺/Ag, +0.80 V. Which ion is the strongest oxidizing agent? Purdue University, General Chemistry Topic Review, "Electrochemical Reactions"; course topic 9.9
  • Standard reduction potentials: Mg²⁺/Mg, −2.38 V; Zn²⁺/Zn, −0.76 V; Cu²⁺/Cu, +0.34 V; Ag⁺/Ag, +0.80 V. Which metal is the strongest reducing agent? Purdue University, General Chemistry Topic Review, "Electrochemical Reactions"; course topic 9.9
  • Standard reduction potentials: Mg²⁺/Mg, −2.38 V; Zn²⁺/Zn, −0.76 V; Cu²⁺/Cu, +0.34 V; Ag⁺/Ag, +0.80 V. Which pair of half-cells gives the galvanic cell with the largest E°? Purdue University, General Chemistry Topic Review, "Electrochemical Reactions"; course topic 9.9
  • Standard reduction potentials: Zn²⁺ + 2 e⁻ → Zn, −0.76 V; Cu²⁺ + 2 e⁻ → Cu, +0.34 V. What is E° for the cell reaction Zn + Cu²⁺ → Zn²⁺ + Cu? Purdue University, General Chemistry Topic Review, "Electrochemical Reactions"; course topic 9.9
  • To balance electrons, the half-reaction Ag⁺ + e⁻ → Ag (E° = +0.80 V) is multiplied by 2. What is its potential now? Purdue University, General Chemistry Topic Review, "Electrochemical Reactions"; course topic 9.9
  • What value is assigned to the standard potential of the half-reaction 2 H⁺ + 2 e⁻ → H₂? Purdue University, General Chemistry Topic Review, "Electrochemical Reactions"; course topic 9.9
  • Will copper metal dissolve in 1 M HCl to give H₂ gas under standard conditions? Cu²⁺ + 2 e⁻ → Cu, +0.34 V; 2 H⁺ + 2 e⁻ → H₂, 0.00 V. Purdue University, General Chemistry Topic Review, "Electrochemical Reactions"; course topic 9.9
  • Zinc metal reacts with acid: Zn + 2 H⁺ → Zn²⁺ + H₂. Given Zn²⁺ + 2 e⁻ → Zn, E° = −0.76 V, what is E° for the reaction? Purdue University, General Chemistry Topic Review, "Electrochemical Reactions"; course topic 9.9

Topic 9.10: Cell potential under nonstandard conditions 10

  • A concentration cell has two copper electrodes, one in 0.010 M Cu²⁺ and one in 1.0 M Cu²⁺. Which way do electrons flow through the wire? College Board, AP Chemistry Course and Exam Description, topic 9.10, essential knowledge 9.10.A.3
  • A galvanic cell runs until its reaction reaches equilibrium. What is its cell potential then? College Board, AP Chemistry Course and Exam Description, topic 9.10, essential knowledge 9.10.A.3
  • As a battery is used, what happens to the reaction quotient Q of its cell reaction and to its voltage? College Board, AP Chemistry Course and Exam Description, topic 9.10, essential knowledge 9.10.A.1
  • By the course description, why do arguments from Le Châtelier's principle not apply to a working electrochemical cell? College Board, AP Chemistry Course and Exam Description, topic 9.10, essential knowledge 9.10.A.2
  • For Zn + Cu²⁺ → Zn²⁺ + Cu, a cell is built with [Zn²⁺] = 1.0 M and [Cu²⁺] = 2.0 M. How does its potential compare with E°? College Board, AP Chemistry Course and Exam Description, topic 9.10, essential knowledge 9.10.A.3
  • For Zn + Cu²⁺ → Zn²⁺ + Cu, a cell is built with [Zn²⁺] = 2.0 M and [Cu²⁺] = 0.10 M. How does its potential compare with E°? College Board, AP Chemistry Course and Exam Description, topic 9.10, essential knowledge 9.10.A.3
  • In the Nernst equation, E = E° − (RT/nF) ln Q, what is true of E when Q is less than 1? College Board, AP Chemistry Course and Exam Description, topic 9.10, essential knowledge 9.10.A.4
  • The standard cell potential E° is the potential of a cell when the reaction quotient Q has which value? College Board, AP Chemistry Course and Exam Description, topic 9.10, essential knowledge 9.10.A.3
  • Two cells run the same reaction. In cell A, Q is far smaller than K. In cell B, Q is only a little smaller than K. Which has the larger potential? College Board, AP Chemistry Course and Exam Description, topic 9.10, essential knowledge 9.10.A.1
  • The voltage of a battery stays nearly steady for most of its life and then drops fast. What explains the steady part? Purdue University, General Chemistry Topic Review, "Electrochemical Reactions"; course topic 9.10

Topic 9.11: Electrolysis and Faraday's law 13

  • A current of 2.00 A flows for 30.0 minutes. How much charge has passed? Use I = q/t. Purdue University, General Chemistry Topic Review, "Electrolytic Cells"; course topic 9.11
  • A current of 3.00 A plates silver from a solution of Ag⁺ for 1,930 s. What mass of silver is deposited? (Ag = 107.87 g/mol, F = 96,485 C/mol) College Board, AP Chemistry Course and Exam Description, topic 9.11, essential knowledge 9.11.A.1
  • A current of 5.00 A is passed through molten NaCl for 9,650 s. How many moles of sodium metal form? (F = 96,485 C/mol) Purdue University, General Chemistry Topic Review, "Electrolytic Cells"; course topic 9.11
  • Aluminum metal is made by reducing Al³⁺. How many moles of electrons are needed to produce 2.00 mol of aluminum? Purdue University, General Chemistry Topic Review, "Electrochemical Reactions"; course topic 9.11
  • Electrolysis of a molten chromium salt deposits 0.100 mol of chromium metal when 0.300 mol of electrons has passed. What is the charge of the chromium ion in the salt? College Board, AP Chemistry Course and Exam Description, topic 9.11, essential knowledge 9.11.A.1
  • How long must a current of 2.00 A run to deposit 0.0500 mol of nickel from a solution of Ni²⁺? (F = 96,485 C/mol) College Board, AP Chemistry Course and Exam Description, topic 9.11, essential knowledge 9.11.A.1
  • How many moles of electrons are in 9,650 C of charge? (F = 96,485 C/mol) Purdue University, General Chemistry Topic Review, "Electrolytic Cells"; course topic 9.11
  • How many moles of electrons must pass to deposit 1 mol of copper metal from a solution of Cu²⁺? College Board, AP Chemistry Course and Exam Description, topic 9.11, essential knowledge 9.11.A.1
  • In an electrolytic cell, 0.200 mol of electrons reduces Cu²⁺ to copper metal. What mass of copper is deposited? (Cu = 63.55 g/mol) College Board, AP Chemistry Course and Exam Description, topic 9.11, essential knowledge 9.11.A.1
  • In an electroplating run, both the current and the time are doubled. By what factor does the mass of metal deposited change? Purdue University, General Chemistry Topic Review, "Electrolytic Cells"; course topic 9.11
  • The same current passes for the same time through a cell that plates silver from Ag⁺ and a cell that plates copper from Cu²⁺. How do the amounts of metal compare? College Board, AP Chemistry Course and Exam Description, topic 9.11, essential knowledge 9.11.A.1
  • What current deposits 0.0100 mol of copper from a solution of Cu²⁺ in 965 s? (F = 96,485 C/mol) College Board, AP Chemistry Course and Exam Description, topic 9.11, essential knowledge 9.11.A.1
  • What does Faraday's constant, F, give? Purdue University, General Chemistry Topic Review, "Electrolytic Cells"; course topic 9.11

How this list was compiled: Our own questions, written to the electrochemistry topics of Unit 9 (Thermodynamics and Electrochemistry) of the College Board's AP Chemistry Course and Exam Description, effective fall 2024, https://apcentral.collegeboard.org/media/pdf/ap-chemistry-course-and-exam-description.pdf, read 2026-10-11: 9.8 Galvanic (Voltaic) and Electrolytic Cells, 9.9 Cell Potential and Free Energy, 9.10 Cell Potential Under Nonstandard Conditions and 9.11 Electrolysis and Faraday's Law. Each fact and each potential was read on 2026-10-11 in the public page named under its question: the General Chemistry Topic Review of Purdue University, the course description itself or a Wikipedia article. Every calculated answer was worked a second time from the numbers in the question. Licence: Own work. Short quotations from the public documents named under each question.

How it works

This AP Chem electrochemistry practice test has 55 questions of our own. It is unofficial and not affiliated with the College Board, which owns AP.

Read the full guide

Where electrochemistry sits

In the College Board's course description, effective fall 2024 and read October 11, 2026, electrochemistry is the last four topics of Unit 9, Thermodynamics and Electrochemistry. The bank follows them: 9.8, galvanic and electrolytic cells (17 questions); 9.9, cell potential and free energy (15); 9.10, cell potential under nonstandard conditions (10); and 9.11, electrolysis and Faraday's law (13). The description gives topics no weights, so the spread is ours.

Potentials and sources

A question prints every reduction potential and constant it needs. The values and rules were read in a Purdue University chemistry review, the course description or a Wikipedia article, named under each answer, and every calculated answer was worked twice.

  • Oxidation is at the anode and reduction at the cathode in every cell, galvanic or electrolytic.
  • E° of a cell is the cathode's reduction potential minus the anode's. Never multiply a potential by a coefficient.
  • For Faraday's law go from amperes and seconds to coulombs, then to moles of electrons, then to moles of metal.

Questions and answers

What unit is electrochemistry in AP Chemistry?

Unit 9, Thermodynamics and Electrochemistry, topics 9.8 to 9.11. Unit 7 is Equilibrium, though a class or a textbook may number its own electrochemistry unit 7. Unit 9 carries 7 to 9% of the multiple-choice section, by the course description, thermodynamics topics included.

Do you need the Nernst equation for the AP Chemistry exam?

Only as reasoning. The course description says calculations with the Nernst equation are not enough to show understanding; you should be able to say how a change in concentration moves the cell potential above or below E°.

Do you have to label electrodes positive or negative on the AP Chemistry exam?

No. The course description says labeling electrodes positive or negative is not assessed. Know which electrode is the cathode and which the anode, and which way the electrons and the ions move.

Are these real AP Chemistry exam questions?

No. They are our own, written from the four electrochemistry topics of Unit 9. No question of the College Board's is copied or reworded here, and this is not a Progress Check.

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