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) Reaction of Copper with Concentrated Nitric Acid:

When copper (Cu) reacts with concentrated nitric acid (HNO₃), it undergoes an oxidation-reduction reaction, forming copper nitrate (Cu(NO₃)₂), nitrogen dioxide (NO₂), and water.

(b) Balanced Chemical Equation:

\[\ce{Cu + 4HNO3 -> Cu(NO3)2 + 2NO2↑ + 2H2O}\]

(c) Names of Reactants and Products:

Reactants	Products
Copper (Cu)	Copper (II) Nitrate (Cu(NO3)2)
Nitric Acid (HNO3)	Nitrogen Dioxide (NO2)
	Water H2O

1. Copper reacts with concentrated nitric acid, dissolving to form a blue solution of copper (II) nitrate.
2. Reddish-brown fumes of nitrogen dioxide (NO₂) gas are released.
3. Water is also formed as a by product.