Question

The ratio of weight of hydrogen and magnesium deposited by the same amount of electricity from $H_2{SO}_4$ and ${MgSO}_4$ in aqueous solution are:

• A. $1:8$
• B. $1:12$
• C. $1:16$
• D. none of these

Answer 1

The correct option is D none of these

According to Faraday's second law of electrolysis,

$\frac{W_1}{W_2}=\frac{E_1}{E_2}$

whereas, w is the weight of the substance deposited (in grams) while E is its chemical equivalent weight in gms per equivalent.

As we know that,

Equivalent weight $=\frac{wt.}{f}$; whereas, f = valence factor

Valence factor of $H_{2}S{O}_4=2$

Mol. wt. of $H_{2}S{O}_4=98g$

Valence factor of $MgS{O}_4=2$

Mol. wt. of $MgS{O}_4=120g$

$\therefore$ Eq. wt. of $H_{2}S{O}_4=\frac{98}{2}=49$

Eq. wt. of $MgS{O}_4=\frac{120}{2}=60$

$\therefore \frac{W_{H_{2}S{O}_4}}{W_{MgS{O}_4}}=\frac{49}{60}$

$\Rightarrow W_{H_{2}S{O}_4}:W_{MgS{O}_4}=49:60$