Question

A current of $2$ amp when passed for $5$ hours through a molten salt deposits $22.2\mathrm{g}$ of metal of atomic mass $177$. The oxidation state of the metal in the metal salt is:

• (A) $+1$
• (B) $+2$
• (C) $+3$
• (D) $+4$

Answer 1

The Correct Option is C

Explanation:
$\mathrm{W}=\frac{\mathrm{ItE}}{96500}$$\therefore \mathrm{E}=\frac{\mathrm{W}\times 96500}{\mathrm{It}}$$=\frac{22.2\times 96500}{2\times 5\times 3600}$$=59.5$Equivalent mass $(E)=\frac{\text{ Atomic mass }}{\text{ oxidation state }}$$\Rightarrow 59.5=\frac{177}{\mathrm{n}}$$\Rightarrow \mathrm{n}=\frac{177}{59.5}$$\therefore \mathrm{n}=2.97\approx 3$Hence, the correct option is (C).