Question

A brown substance 'X' on heating in air forms a substance 'Y'. when hydrogen gas is passed over heated 'Y', it again changes back in 'X'. i) Name the substance 'X' and 'Y'. ii) Name the reaction and write the chemical equation's involved.

Answer 1

1. the substance x is copper and substance y is copper oxide.

2. the chemical process occuring during two changes is:- Oxidation and reduction.

3. The chemical equations involved are:-
2Cu (s) + O2 (g) ----> 2CuO

Answer 2

copper dioxide
reduction and oxidation