Question

1. What happens when copper reacts with concentrated nitric acid? What is the colour of the gas released during the reaction?
2. Write its balanced chemical equation.
3. Write the names of reactants and products.

Answer 1

a. When copper (Cu) reacts with concentrated nitric acid (HNO₃), it undergoes an oxidation-reduction reaction forming copper nitrate and a reddish-brown poisonous nitrogen dioxide gas with water.

b. \[\ce{Cu + \underset{(conc.)}{4HNO3} -> Cu(NO3)2 + 2NO2 + 2H2O}\]

c. Reactants: Copper and concentrated nitric acid.

Products: Copper nitrate, nitrogen dioxide and water.