Consider the following displacement reaction in which Fe displaces Cu from CuSO4 to form FeSO4:
{πΉπ(π ) \over πΌπππ} + {πΆπ’ππ_4(ππ) \over\ copper\ sulphate\ (π΅ππ’π)} β {πΉππO_4(aq) \over Iron\ (II) sulphate\ (πΊππππ)} + {πΆπ’(π ) \over πΆπππππ\ (π πππππ ββππππ€π)}In the above reaction, Fe is gaining oxygen. Hence, Fe is oxidised. CuSO4 is loosing oxygen. Hence, it is reduced. So, it is a redox reaction.