What does Faraday's law state?
The mass deposited at an electrode is proportional to the electric charge passed (current × time). Double the charge, double the metal.
// chemistry › Electrolysis
Faraday's Law of Electrolysis
Calculate mass deposited in electrolysis W = EIt/96500, with symbol legend and real-world examples.
W = \frac{E\,I\,t}{96500}
A mind behind this: Michael Faraday 1791–1867
Frequently asked questions
Where is it used day to day?
Electroplating jewellery and car parts with gold, silver or chrome; refining copper for wires; anodising aluminium. Anywhere electricity deposits or dissolves metal.
What is the Faraday constant (96500)?
The charge carried by one mole of electrons. It bridges electric charge and moles of substance, so you can turn amps and seconds into grams.
What is equivalent weight here?
Molar mass divided by the electrons needed per ion. Copper from Cu²⁺ needs 2 electrons, so its equivalent weight is 63.5 ÷ 2.
How does the example give 0.02 g?
Charge = 2 A × 965 s = 1930 C. Divided by 96500 gives 0.02 mole-equivalents, and with E = 1 that is 0.02 g.