Question

To deposit 0.634 g of copper by electrolysis of aqueous cupric sulphate solution, the amount of electricity required (in coulombs) is:

• A. 1930
• B. 3960
• C. 4825
• D. 9650

Hint:

Use Faraday's law to calculate the amount of electricity required for electrolysis by considering the mass of the substance, its molar mass, and valency.

Answer 1

The Correct Option is A

Step 1: Use Faraday’s Law of Electrolysis.
The amount of electricity required is given by: \[ Q = \frac{m M}{z F} \] where \( m \) is the mass of the substance deposited, \( M \) is the molar mass of copper, \( z \) is the valency of copper, and \( F \) is Faraday's constant.

Step 2: Apply the values.
For copper, \( M = 63.5 \, \text{g/mol} \), \( z = 2 \), and \( F = 96500 \, \text{C/mol} \). Substituting the values, we get: \[ Q = \frac{0.634 \times 63.5}{2 \times 96500} \approx 1930 \, \text{C} \]