Question:
$5 \mathrm{~g}$ of zinc is treated separately with an excess of
(A) dilute hydrochloric acid and
(B) aqueous sodium hydroxide.
The ratio of the volumes of $\mathrm{H}_{2}$ evolved in these two reactions is:
Correct Option: , 2
Solution:
$\mathrm{Zn}+2 \mathrm{NaOH} \rightarrow \mathrm{Na}_{2} \mathrm{ZnO}_{2}+\mathrm{H}_{2}$
$\mathrm{Zn}+2 \mathrm{HCl} \rightarrow \mathrm{ZnCl}_{2}+\mathrm{H}_{2}$
$\mathrm{NaOH}$ and $\mathrm{HCl}$ reacts with a certain amount of zinc to produce equal number of moles of $\mathrm{H}_{2}$.