Answer to Question #295449 in Physical Chemistry for feyintola

Question

a solution of gold (3) trioxonitrate (5) is electrolysed using a current of 25mA until 1.2g of gold is deposited at the cathode . what is the amount of electricity that would have passsed through the solution. and how long will it take for such an amount of gold to be deposited. then calculate the volume of the gas liberated at the anode.

Answer 1

Faradays constant $=96485$

Molar mass of Gold $=196.967g/mol$

Au$^{3+}+3e^-\to$ Au$_{(s)}$

1 mole of Au$^{3+}$ requires 3 faradays

Charge required for 1.2g

$\frac{1.2}{196.967}×3×96485$

$=1763.5C$

$\frac{25}{1000}t=1763.5$

$t=70540$ seconds