Question

Assertion: In the reaction, $2C{u}_2{O}_{\left(s\right)}+C{u}_2{S}_{\left(s\right)}\to 6C{u}_{\left(s\right)}+S{O}_{2\left(g\right)}$ copper acts as a reductant and sulphur acts as an oxidant.
Reason: The given reaction is not a redox reaction.

• A. If both assertion and reason are true and reason is the correct explanation of assertion.
• B. If both assertion and reason are true but reason is not the correct explanation of assertion.
• C. If assertion is true but reason is false.
• D. If both assertion and reason are false.

Answer 1

Answer: (D)

The oxidation states are as :

Copper is reduced from $+1$ state to zero. Sulphur is oxidised from $-2$ state to $+4$. $C{u}_{2}O$ helps sulphur in $C{u}_{2}S$ to increase its oxidation number, hence $Cu(I)$ is an oxidant and sulphur of $C{u}_{2}S$ helps copper both in $C{u}_{2}S$ and $C{u}_{2}O$ to decrease its oxidation number, hence $S$ of $C{u}_{2}S$ is a reductant. And the reaction is redox reaction.