Question

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

• A. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion
• B. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion
• C. Assertion is correct but Reason is incorrect
• D. Both Assertion and Reason are incorrect

Answer 1

The correct option is D Both Assertion and Reason are incorrect

The oxidation states are as :

$2{\stackrel{+1}{Cu}}_2{\stackrel{-2}{O}}_{(}s)+{\stackrel{+1}{Cu}}_2{\stackrel{-2}{S}}_{(}s)$ $\to$ $6{\stackrel{0}{Cu}}_{(}s)$+ $\stackrel{+4}{S}{\stackrel{-2}{O}}_{2\left(g\right)}$

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