Question

Consider the reaction:

$H_{2}S{O}_{3\left(aq\right)}+S{n}_{\left(aq\right)}^{4+}+H_2{O}_{\left(l\right)}\to$$S{n}_{\left(aq\right)}^{2+}+HS{O}_{4\left(aq\right)}^{-}+3H_{\left(aq\right)}^{+}$

Which of the following statement is correct?

• A. $S{n}^{4+}$ is the oxidizing agent because it undergoes oxidation
• B. $S{n}^{4+}$ is the reducing agent because it undergoes oxidation
• C. $H_{2}S{O}_3$ is the reducing agent because it undergoes oxidation
• D. $H_{2}S{O}_3$ is the oxidizing agent because it undergoes reduction

Answer 1

The correct option is C $H_{2}S{O}_3$ is the reducing agent because it undergoes oxidation

The oxidation number of sulphur in $H_{2}S{O}_3$ is $+4$ and it get oxidises to $+6$ in $HS{O}_4^{-}$.

$S{n}^{4+}$ get reduced to $S{n}^{2+}$ in the given reaction.

We can say that $H_{2}S{O}_3$ is the reducing agent because it undergoes oxidation.

Hence, option $C$ is correct.