Question

State Faraday's first law of electrolysis. For the electrode reaction $Z{n}^{2+}+2e^{-}\to Z{n}_{\left(s\right)}$, what quantity of electricity in coulombs required to deposit one mole of zinc?

Answer 1

Faraday's First law of electrolysis:
The amount of substance that undergoes oxidation or reduction at each electrode during electrolysis is directly proportional to the amount of electricity that passes through the cell.
Mathematical form :
(i) Moles of the substance produced $=\frac{I\left(A\right)\times t\left(s\right)}{96500\left(C/mol{e}^{-}\right)}\times$ mole ratio from stoichiometry
(ii) Mass of the substance produced $=\frac{I\left(A\right)\times t\left(s\right)}{96500\left(C/mol{e}^{-}\right)}\times$ mole ratio $\times$ molar mass of the substance
2 faraday are required to deposit one mole of zinc. This is because 2 moles of electrons are required to deposit one mole of zinc.This corresponds to $2\times 96500=193000$ coulombs.