Question

Question 56

Explain the given reaction with examples:

(a) Hydrogenation
(b) Oxidation
(c) Substitution
(d) Saponification
(e) Combustion

Answer 1

(a) Unsaturated hydrocarbons and hydrogen in the presence of nickel catalyst to give saturated hydrocarbons.

${\text{CR}}_2={\text{CR}}_2+{\text{H}}_2\to {\text{CR}}_2\text{H}-{\text{CR}}_2\text{H}$

(b) Ethanol is oxidised to ethanoic acid in presence of alkaline ${\text{KMnO}}_4$ on heating.

${\text{CH}}_3{\text{CH}}_2\text{OH}\to {\text{CH}}_3\text{COOH}$

(c) In presence of sunlight, chlorine is added to hydrocarbons.

${\text{CH}}_4+{\text{Cl}}_2\to {\text{CH}}_3\text{Cl}+\text{HCl}$

(d) Used in preparation of soap.

${\text{CH}}_3{\text{COOC}}_2{\text{H}}_5+\text{NaOH}\to {\text{CH}}_3\text{COO Na}+{\text{C}}_2{\text{H}}_5\text{OH}$

(e) Carbon compounds release a large amount of heat and light on burning.

${\text{CH}}_4+2{\text{O}}_2\to {\text{CO}}_2+2{\text{H}}_2\text{O}+\text{sunlight + heat}$