AP Chemistry Flashcards: Electrolysis and Faraday's Law
Written by AP Content Team, Verified for 2026 AP Exams, Last updated: May 2026
Review key ideas with interactive flashcards. This set includes 10 cards to help you master important concepts.
Why is a balanced half-reaction essential for calculating the amount of substance produced in electrolysis?
The balanced half-reaction provides the crucial mole ratio between the electrons transferred and the amount of substance produced or consumed at the electrode.
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Why is a balanced half-reaction essential for calculating the amount of substance produced in electrolysis?
The balanced half-reaction provides the crucial mole ratio between the electrons transferred and the amount of substance produced or consumed at the electrode.
What is the fundamental purpose of applying an external electrical energy source in electrolysis?
The external energy source provides the necessary energy to force a non-spontaneous redox reaction to occur, which it would not do on its own.
List the three main components used in dimensional analysis to find the amount of substance produced from current and time.
The three components are the total charge (q = I × t), the Faraday constant (F), and the mole ratio of electrons to substance from the half-reaction.
Summarize the overall calculation pathway to determine the amount of a substance produced during electrolysis.
First, calculate total charge (q) from current and time. Then, use the Faraday constant to convert charge to moles of electrons, and finally use the half-reaction's mole ratio to find moles of substance.
What is electrolysis?
Electrolysis is the process of using an external electrical energy source to drive a thermodynamically unfavorable (non-spontaneous) redox reaction.
What is the Faraday constant (F)?
The Faraday constant (F) represents the charge per mole of electrons, with a value of approximately 96,485 Coulombs per mole of electrons (C/mol e⁻).
If a current of 2.0 A runs for 500 seconds, what is the total charge passed through the electrolytic cell?
Using the formula q = I × t, the total charge is (2.0 A) × (500 s) = 1000 Coulombs.
State the equation for Faraday's Law that relates charge, current, and time.
Faraday's Law is expressed as q = I × t, where q is charge in Coulombs, I is current in Amperes, and t is time in seconds.
How is the Faraday constant used as a conversion factor in electrolysis calculations?
The Faraday constant is used to convert the total charge (q) in Coulombs that has passed through a cell into the corresponding number of moles of electrons.
What is the first step in a stoichiometric calculation for electrolysis after determining the total charge (q)?
The first step is to use the Faraday constant (F ≈ 96,485 C/mol e⁻) to convert the total charge in Coulombs into moles of electrons.