Question

Which compound act as oxidising agent only.

(1)$S{O}_2$

(2)$H_{2}S$

(3)$H_{2}S{O}_4$

(4)$HN{O}_2$

Answer 1

Hint: The compound which has the tendency to reduce only or which is present in its maximum oxidation state will act as only oxidising agent.

Explanation for correct option:

(3) The oxidation state of sulphur in $H_{2}S{O}_4$ is +6, which is the maximum oxidation state for sulphur. So, sulphuric acid will act as only oxidising agent.

Explanation for incorrect options:

(1) The oxidation state of sulphur in $S{O}_2$is +4.

(2) The oxidation state of sulphur in $H_{2}S$ is -2.

(4) The oxidation state of nitrogen in $HN{O}_2$ is +3 but maximum oxidation state of nitrogen is +5.

Hence, option (3) is correct.