Justify that the reaction
`2Cu_(2)O_(s)+Cu_(2)S(s)rarr6Cu(s)+SO_(2)(g)` a redox reaction. Identify the species oxidised`//`reduced. Which acts as an oxidanat and which acts as a reductant?

Answer

A, C, D

Explanation

`2Cuoverset(+1)Cu_(2)(s)+overset(+1-2)(Cu_(2)S(s))rarr6overset(0)Cu(s)+overset(+4-2)(SO_(2))`
In the reaction, `Cu` is reduced from `+1` oxidation state to `0` oxidation state and `S` is oxidised from `-2` to `+4` state. Thus, it is a redox reaction.
Moreover, `Cu_(2)O` helps `S` in `Cu_(2)S` to incerease its oxidation number, therefore `Cu^(1+)` is an oxidant and `S` in `Cu_(2)S` helps `Cu` both in `Cu_(2)S` itself and `Cu_(2)O` to decrease its oxidation number, therefore, `S` in `Cu_(2)S` is reductant.