In the reaction below, identify the species undergoing oxidation and reduction. $ \text{H}_2\text{S}(\text{g})+\text{Cl}_2(\text{g})\rightarrow2\text{HCl}(\text{g})+\text{S}(\text{s}) $
Answer & explanation
Correct answer: option 1
The correct answer is Option (1) → $H_2S$ is oxidized and $Cl_2$ is reduced
In $H_2S$: Sulfur is in the –2 oxidation state.
In product S (elemental sulfur): Oxidation state = 0
Therefore there is increase in oxidation state → oxidation.
In $Cl_2$: Chlorine is in the 0-oxidation state.
In $HCl$: Chlorine is in the –1 oxidation state
Therefore there is decrease in oxidation state → reduction.
$H_2S$ is oxidized and $Cl_2$ is reduced.