Question

Which of the following statements are correct?

(i) S – S bond is present in $$\mathrm{H}{\phantom{A}}_2\mathrm{S}{\phantom{A}}_2\mathrm{O}{\phantom{A}}_6$$.

(ii) In peroxosulphuric acid $$(\mathrm{H}{\phantom{A}}_2\mathrm{SO}{\phantom{A}}_5)$$ sulphur is in +6 oxidation state.

(iii) Iron powder along with $$\mathrm{Al}{\phantom{A}}_2\mathrm{O}{\phantom{A}}_3$$ and $$\mathrm{K}{\phantom{A}}_2\mathrm{O}$$ is used as a catalyst in the preparation of $$\mathrm{NH}{\phantom{A}}_3$$ by Haber’s process.

(iv) Change in enthalpy is positive for the preparation of $$\mathrm{SO}{\phantom{A}}_3$$ by catalytic oxidation of $$\mathrm{SO}{\phantom{A}}_2$$.

Answer 1

(i) S – S bond is present in $$\mathrm{H}{\phantom{A}}_2\mathrm{S}{\phantom{A}}_2\mathrm{O}{\phantom{A}}_6$$.

(ii) In peroxosulphuric acid $$(\mathrm{H}{\phantom{A}}_2\mathrm{SO}{\phantom{A}}_5)$$ sulphur is in +6 oxidation state.

Explanation:

$$\begin{array}{c}\mathrm{O}\phantom{...}\mathrm{O}\\ ||\phantom{...}||\\ \underset{//\phantom{...}|\phantom{........}|\phantom{...}\mathrm{\setminus }\mathrm{\setminus }}{\mathrm{S}-\mathrm{S}}\\ \mathrm{O}\phantom{..}\mathrm{OH}\phantom{.}\mathrm{OH}\phantom{.}\mathrm{O}\end{array}$$

In $$\mathrm{H}{\phantom{A}}_2\mathrm{SO}{\phantom{A}}_5$$, there is a peroxo-linkage.

(O in peroxide linkage has oxidation state – 1)