Q1. Zn + CuSO4 -> ZnSO4 + Cu Which substance is being oxidised in the above reaction?
A Zn Correct
B ZnSO4
C Cu
D CuSO4
Explanation
Oxidation means loss of electrons or an increase in oxidation state. In this displacement reaction, zinc changes from Zn to Zn2+ in ZnSO4, so zinc loses electrons and is oxidised. ZnSO4 is the product after zinc has already been oxidised, not the substance undergoing oxidation in the reactant side. Cu is deposited as metallic copper after copper ions gain electrons, so it represents reduction. CuSO4 contains Cu2+ ions, which are reduced to Cu, not oxidised.