Question

The number of Faradays (F) required to produce 20 g of calcium from molten CaCl₂ (Atomic mass of Ca = 40 g mol⁻¹) is ______.

Options

• 1

• 2

• 3

• 4

Answer 1

The number of Faradays (F) required to produce 20 g of calcium from molten CaCl₂ (Atomic mass of Ca = 40 g mol⁻¹) is 1.
Explanation:

In electrolysis of molten CaCl₂, the reaction is:

\[\ce{Ca^{2+} + 2e- -> Ca}\]

This shows that 2 Faradays are required to deposit 1 mole (40 g) of calcium.

So, to produce 20 g of Ca (i.e., 0.5 mole), the required charge = 0.5 × 2

= 1 F