Cu2++2e−───▸Cu .........(i) According to Faraday's first law, when an electric current is passed through an electrolyte, amount of substance deposited is directly proportional to the quantity of electric charge passed through the electrolyte. ∵1mol of 63.5g of Cu is obtained by passing 2F of electricity. Mass of Cu obtained by passing 1F of electricity =
63.5
2
g ∴ Mass of Cu ontained by passing 0.5F of electricity =