Question

A brown coloured substance "X' on heating in air forms a substance 'Y'. When hydrogen gas.
is passed over heated 'Y', it again changes back into 'X'.
A. Name the substance 'X' and 'Y'.
B. Write chemical reactions involved in both the changes​

Answer 1

Answer:

X - Copper

Y- Copper oxide

In first change oxidation reaction takes place

In the second change reduction takes place.

Answer 2

Answer:

X is copper

y is copper oxide ( CuO)

1,

Cu + O2 ----> CuO

2. CuO + H2 ---> cu + H20