Question

$S{O_2}$ acts as
(This question has multiple correct options)
A. Bleaching agent
B. Oxidising agent
C. Reducing agent
D. Disinfectant

Answer 1

Hint: In order to answer this question, to know the usage or act of $S{O_2}$, we should go through every reaction of $S{O_2}$ in which it may act as the given options. We check all conditions separately with the help of reaction examples.

Complete step-by-step answer:
$S{O_2}$ exhibits bleaching action due to its reduction action. Due to its reduction action, $S{O_2}$ removes oxygen from coloured substance making it colourless.
Example - $S{O_3}^{2 - }(aq) + [dye - O] \to S{O_4}^{2 - }(aq) + [dye]$
Hence, $S{O_2}$ is a bleaching agent.
Now, in $S{O_2}$ , Oxidising state of $S$ is $ + 4$ . It can either lose its two electrons by which the oxidation state of Sulphur will change to $ + 6$ or it can gain electrons to attain $ - 2$ oxidation state.
Example - Sulphur acts as oxidation agent-
$S{O_2} + 2{H_2}S \to 3S + 2{H_2}O$
Similarly, Sulphur acts as reducing agent-
$S{O_2} + C{l_2} \to S{O_2}C{l_2}$
Hence, sulphur acts as both oxidising and reducing agent.
And also $S{O_2}$ is used as a disinfectant. Due to this, it is used in preserving foods.

Hence, all options are correct.

Note: Sulphur dioxide is found on Earth and exists in very small concentrations and in the atmosphere at about \[1{\text{ }}ppm\] . On other planets, sulphur dioxide can be found in various concentrations, the most significant being the atmosphere of Venus, where it is the third-most significant atmospheric gas at $150\,ppm$.