Faraday's laws of electrolysis
Electrolysis uses electric current to drive a non-spontaneous redox reaction. Faraday's laws relate the mass of substance deposited/dissolved to the charge passed:
Charge (Q) = I × t
Moles deposited = Q / (n × F)
Mass = moles × molar mass
Where F = 96,485 C/mol (Faraday's constant) and n = electrons per atom.