Q12 / 150 · MHT CET 2021 (20 Sep Shift 1) · Chemistry
How many faraday of electricity is required to produce $10 \mathrm{~g}$ of calcium metal (molar mass $=40 \mathrm{~g} \mathrm{~mol}^{-1}$ ) from calcium ions?
- A$1.5 \mathrm{~F}$
- B$2.0\mathrm{~F}$
- Correct answerC$0.50 \mathrm{~F}$
- D$1.0 \mathrm{~F}$
Solution
$$
2 \mathrm{e}^{-}+\mathrm{Ca}^{2+} \longrightarrow \mathrm{Ca}_{(\mathrm{s})}
$$
Charge of $1 \mathrm{~mol}$ electron $=1$ faraday of electricity To produce $1 \mathrm{~mol}$ calcium metal $2 \mathrm{~F}$ electricity is required Moles of calcium $=\frac{10}{40}=0.25$
To produce $0.25 \mathrm{~mol}$ calcium electricity required $=2 \times 0.25=0.5 \mathrm{~F}$
Hence, the correct answer is option: 'C'.