AP Chemistry / Unit 9: Thermodynamics and Electrochemistry
9.11 Electrolysis and Faraday's Law
Notes
Charge: $q=It$ (coulombs = amps × seconds). Moles of electrons $\displaystyle =\frac{q}{F}$, $F=96{,}485$ C/mol.
- Use the half-reaction to convert moles of electrons to moles of metal.
Practice
A current of 2.0 A for 965 s passes how many moles of electrons?
$\displaystyle \frac{1930}{96485}\approx0.020$.
$Cu^{2+}+2e^-\to Cu$. 0.02 mol $e^-$ deposits how many mol of Cu?
2 electrons per Cu.
Doubling the time of electrolysis at the same current:
$q=It$.
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