Question: Among the following reactions of hydrogen with halogens, the one that requires a catalyst is :
$\mathrm{H}_{2}+\mathrm{I}_{2} \rightarrow 2 \mathrm{HI}$
$\mathrm{H}_{2}+\mathrm{F}_{2} \rightarrow 2 \mathrm{HF}$
$\mathrm{H}_{2}+\mathrm{Cl}_{2} \rightarrow 2 \mathrm{HCI}$
$\mathrm{H}_{2}+\mathrm{Br}_{2} \rightarrow 2 \mathrm{HBr}$
Correct Option: 1
Solution:
$\mathrm{H}_{2}+\mathrm{I}_{2} \rightarrow 2 \mathrm{HI}$
