Metal X was placed in lead nitrate solution. A thin layer of lead metal deposits on metal X. Which is more reactive metal X or lead ? State the type of reaction and give an example of this type.

Metal X is more active metal because it displaced the metal lead from lead nitrate. It is a displacement reaction.

CuSO₄ + Zn ⟶ ZnSO₄ + Cu

Zn is more active metal than Cu, and it displaces Cu from copper sulphate.