Question

A current of 2 A is passed through molten CaCl\(_2\) for 1930 seconds. What is the mass of calcium deposited at the cathode? (Ca molar mass = 40 g/mol, valency = 2, Faraday's constant = 96500 C/mol)

• A. 0.4 g
• B. 0.8 g
• C. 1.29 g
• D. 1.5 g

Hint:

To find the mass of a substance deposited during electrolysis, use the formula: \[ m = \frac{I \times t \times M}{n \times F} \]

Answer 1

The Correct Option is B

The amount of substance deposited at the cathode is given by the formula: \[ m = \frac{I \times t \times M}{n \times F} \] where: - \(I = 2 \, \text{A}\) (current) - \(t = 1930 \, \text{s}\) (time) - \(M = 40 \, \text{g/mol}\) (molar mass of calcium) - \(n = 2\) (valency of calcium) - \(F = 96500 \, \text{C/mol}\) (Faraday's constant) Substituting the values: \[ m = \frac{2 \times 1930 \times 40}{2 \times 96500} = \frac{154400}{193000} = 0.8 \, \text{g} \] Final answer
Answer: \(\boxed{0.8\, \text{g}}\)