Q16 / 75 · JEE Main 2025 (22 Jan Shift 1) · Chemistry
A solution of aluminium chloride is electrolysed for 30 minutes using a current of 2 A . The amount of the aluminium deposited at the cathode is
[Given : molar mass of aluminium and chlorine are $27 \mathrm{~g} \mathrm{~mol}^{-1}$ and $35.5 \mathrm{~g} \mathrm{~mol}^{-1}$ respectively. Faraday constant $\left.=96500 \mathrm{C} \mathrm{mol}^{-1}\right]$
- A1.660 g
- Correct answerB0.336 g
- C0.441 g
- D1.007 g
Solution
$\mathrm{Al}^{1++}+3 \mathrm{e}^{-} \longrightarrow \mathrm{Al}$
$\begin{aligned}
\text { Moles of electron } & =\frac{2 \times 30 \times 60}{96500} \\
& =\frac{36}{965}
\end{aligned}$
$\begin{aligned}
\text { Moles of } \mathrm{Al} & =\frac{36}{3 \times 965} \\
& =\frac{12}{965}
\end{aligned}$
$\text { Mass of } \mathrm{Al}=\frac{12}{965} \times 27$
$=0.336 \mathrm{gm}$
Hence, the correct answer is option: 'B'.