Question

Moist hydrogen cannot be dried over (conc.) $H_{2}S{O}_4$ because:

• A. it catches fire
• B. it is reduced by $H_{2}S{O}_4$
• C. it is oxidised by $H_{2}S{O}_4$
• D. it decomposes $H_{2}S{O}_4$

Answer 1

The correct option is C it is oxidised by $H_{2}S{O}_4$

Moist hydrogen cannot be dried over (conc.) $H_{2}S{O}_4$ because it is oxidised by $H_{2}S{O}_4$.

$H_{2}S{O}_4\text{(conc.)}+H_2\to 2H_{2}O+S{O}_2$

To remove traces of moisture, $H_2$ gas is collected over $P_2{O}_5$ or anhydrous $CaC{l}_2$.