Question

Explain the following in terms of gain or loss of oxygen with an examples:
(a) Reduction.
(b) Oxidation.

Answer 1

(a)Reduction- Addition of hydrogen or removal of oxygen in a chemical reaction is called reduction.

For example:
a) $\text{CuO}+{\text{H}}_2\to \text{Cu}+{\text{H}}_2\text{O}$
Copper oxide is reduced to copper.

b) ${\text{H}}_2\text{S}+{\text{Cl}}_2\to 2\text{HCl}+\text{S}$
Chlorine is reduced to hydrogen chloride.

(b)Oxidation- Addition of oxygen or removal of hydrogen in a chemical reaction is called oxidation.

For example:
a) $2\text{Cu}+{\text{O}}_2\to 2\text{CuO}$
Copper is oxidised to copper oxide.

b) $4\text{Al}+3{\text{O}}_2\to 2{\text{Al}}_2{\text{O}}_3$
Aluminium is oxidised to aluminium oxide.