Question

State a reaction in which SO2 act as an oxidising agent

Answer 1

Normally, sulphur dioxide is a reducing agent but sometimes it acts as an oxidizing agents too as for example;

In the Claus process, it is reduced by hydrogen sulphide to give elemental sulphur as:

SO2 + 2H2S --> 3S + 2H2O

Answer 2

The following reaction states $S{ O }_{ 2 }$ act as a oxidizing agent.

$S{ O }_{ 2 }\quad +\quad 2{ H }_{ 2 }S\quad \rightarrow \quad 3S\quad +\quad 2{ H }_{ 2 }O$

Oxidizing agent:

Those elements or compounds oxidizes other and itself getting reduced.

For example:

$S{ O }_{ 2 }\quad +\quad 2{ H }_{ 2 }S\quad \rightarrow \quad 3S\quad +\quad 2{ H }_{ 2 }O$

Oxidation states S in $S{ O }_{ 2 }$

$x+2(-2)\quad =\quad 0$

$x\quad =\quad +4$

Oxidation state of S in 3S is zero.

The oxidation state decreased from $3 \rightarrow 0$.

Hence, sulphur is an oxidizing agent.