Arrange the following in increasing order of the mass of the metal deposited when 1 amp of current is passed through their electrolytic solutions for 1 minute.

(A). Al (atomic mass = $27\, g\, mol^{-1}$)
(B). Mg (atomic mass = $24\, g\, mol^{-1}$)
(C). Ag (atomic mass = $108\, g\, mol^{-1}$)
(D). Cu (atomic mass = $63.5\, g\, mol^{-1}$)

Choose the correct answer from the options given below:

(A), (B), (D), (C)

The correct answer is Option (2) → (A), (B), (D), (C)

According to Faraday’s laws of electrolysis, the mass of metal deposited is proportional to its equivalent weight (M / n).

Let’s calculate $\frac{M}{n}$​ for each metal:

• (A) Al³⁺ → $\frac{27}{3} = 9$
• (B) Mg²⁺ → $\frac{24}{2} = 12$
• (D) Cu²⁺ → $\frac{63.5}{2} = 31.75$
• (C) Ag⁺ → $\frac{108}{1} = 108$

Increasing order of mass deposited:

$\text{Al} < \text{Mg} < \text{Cu} < \text{Ag}$