Explain the following with examples:
• Addition reaction.
• combustion reaction.
• Substitute reaction.
Answers
Answer:
Explanation:
(a) Addition of hydrogen to unsaturated hydrocarbon to obtain a saturated hydrocarbon is called hydrogenation reaction. Hydrogenation is used for converting unsaturated vegetable oil into fat. This can be shown by following equation:
CH
2
=CH
2
+H
2
Ni
CH
3
−CH
3
(b) When oxygen is added to alcohol to make carboxylic acid, this is called oxidation reaction. Following is an example of oxidation of alcohol.
CH
3
CH
2
CH
2
OH
alk KMnO
4
//acid K
2
Cr
2
O
7
CH
3
CH
2
COOH
(c) Saturated hydrocarbons are fairly unreactive. But in the presence of sunlight, chlorine substitutes hydrogen one by one.
CH
4
+Cl
2
→CH
3
Cl+HCl (in the presence of sunlight.)
This substitution can go on till, carbon tetrachloride is obtained.
(d) When ester is treated with an alkali, the reaction gives ethanol and sodium ethanoate. This reaction is called saponification reaction because this reaction forms the basis of preparation of soap. This can be given by following equation.
CH
3
COOC
2
H
5
+NaOH→CH
3
COONa+C
2
H
5
OH