Question

Metal plating is done by passing current through a metal solution. For example, an item can become gold plated by attaching the item to a power source and submerging it into a Au3+ solution. The item itself serves as the cathode, at which the Au3+ ions are reduced to Au(s). A piece of solid gold is used as the anode and is also connected to the power source, thus completing the circuit.

What mass of gold is produced when 10.2 A of current are passed through a gold solution for 12.0 min ?

Answer 1

We will use Faraday's law of electrolysis here, accroding to it if one Faraday of charge is passed through an electrolyte then 1 gequivalent of electrolyte is deposited or produced.

The charge passed = Current X time in seconds = 10.2 x 12 X 60 = 7344 Coloumbs

Faraday passed = 7344 / 96500 = 0.0761 Faraday

So gram equivalent deposited = 0.0761 g equivalent

The atomic weight of gold = 197 g / mole

So equivalent weight = 197 / 3

so mass of gold produced = gram equivalent X equivalent weight = 0.0761 X 197 / 3 = 4.997 grams