Question

A reddish brown metal A, when exposed to moist air, forms a green layer B. When A is heated at different temperatures in the presence of $O_2$, it forms two types of oxides - C (black) and D(red). Identify A, B, C, D and write the balanced equation.

Answer 1

It is clear that A is copper developing green layer of $CuC{O}_3$ (B).

$Cu$ forms $2$ types of oxides: $C{u}_{2}O$ and $CuO$

$C{u}_{2}O$ is red while $CuO$ is black.

Hence, A= $Cu$, B= $CuC{O}_3$, C= $CuO$, D= $C{u}_{2}O$ .