Question

When hydrogen is passed over a black solid compound A, the products are 'a colorless liquid' and 'a reddish-brown metal B .’ Substance B is divided into two parts, each placed in separate test tubes.
Dilute HCl is added to one part of substance B and dilute $HN{O}_3$ to the other.​

Write an equation for the reaction between hydrogen and compound A.​

Answer 1

Compound A is copper oxide which reacts with hydrogen and reduces to copper which is a reddish-brown metal along with the formation of water which is a colorless liquid.​ ​

Chemical reaction: ​ ​
$CuO+H_2\to Cu+H_{2}O$ ​