Question

When a piece of lead $\left(\text{Pb}\right)$ is left in blue coloured copper sulphate solution $\left({\text{CuSO}}_4\right)$, the colour of lead changes due to copper deposition. What type of reaction is this?

• A. Displacement reaction
• B. Combination reaction
• C. Neutralization reaction
• D. Decomposition reaction

Answer 1

The correct option is A Displacement reaction

Lead ($\text{Pb}$) is more reactive than copper ($\text{Cu}$), so it displaces copper from copper sulphate solution $({\text{CuSO}}_4$).

The displaced copper deposits on the lead piece so we see change in the colour of lead. The reaction occurs as follows:

$\text{Pb (s)}+{\text{CuSO}}_4\text{(aq)}\to {\text{PbSO}}_4\text{(aq)}+\text{Cu(s)}$

This type of chemical reaction in which a more reactive element displaces a less reactive element from its compound or salt solution is called a displacement reaction.