Which of the following source materials generate $\mathrm{SO}_2$ that is used in contact process?
Which of the following source materials generate $\mathrm{SO}_2$ that is used in contact process?
$\mathrm{S}, \mathrm{FeS}_2$
$\mathrm{S}, \mathrm{FeS}$
$\mathrm{H}_2 \mathrm{~S}, \mathrm{FeS}_2$
$\mathrm{Na}_2 \mathrm{~S}, \mathrm{FeS}_2$
Solution
Preparation of $\mathrm{H}_2 \mathrm{SO}_4$ from iron pyrite $\left(\mathrm{FeS}_2\right)$ : $\mathrm{FeS}_2+\mathrm{O}_2 \rightarrow \mathrm{Fe}_2 \mathrm{O}_3+\mathrm{SO}_2$ and from $\mathrm{S}: \mathrm{S}+\mathrm{O}_2 \rightarrow \mathrm{SO}_2$