Explain the following: (a) Oxidation (b) Reduction
Answer: Oxidation: When a substance gains oxygen or loses hydrogen during a reaction, it is called that the substance is oxidized. This phenomenon is called oxidation. In the following reaction, copper gets oxygen and hence is oxidised.
2Cu + O2 + Heat ⇨ 2CuO
CuO + H2 + Hear ⇨ Cu + H2O
In the above reaction hydrogen gains oxygen, and hence oxidized.
Reduction: If a substance loses oxygen or gains hydrogen during a reaction, it is that the substance is reduced. This phenomenon is called reduction. In the following reaction zinc loses oxygen, and hence called is reduced.
ZnO + C ⇨ ZnCO
MnO2 + 4HCl ⇨ MnCl2 + 2H2O + Cl2
In this reaction Mangnese dioxide loses oxygen and hence is called readuced.