Question

What happens when
(i) Chlorobenzene is treated with $$C{l}_2/FeC{l}_3$$
(ii) Ethyl chloride is treated with $$AgN{O}_2$$
(iii) 2-bromopentane is treated with alcoholic KOH?
Write the chemical equation in support of your answer.

Answer 1

Hint: In the first reaction, when chlorobenzene reacts with $$C{l}_2/FeC{l}_3$$, it will undergo nucleophilic substitution reaction and give multiple products.
In the second reaction, Ethyl chloride is reacted with $$AgN{O}_2$$. This reaction is the Victor Mayer method.
In the third reaction, 2-bromopentane is treated with alcoholic KOH, will follow Saytzeff’s rule and undergo $$\beta -$$ elimination.

Complete step by step answer:
(i) When Chlorobenzene is treated with $$C{l}_2/FeC{l}_3$$, it will lead to the formation of both ortho and para isomers. The ortho isomer will be 1,2-Dichlorobenzene and the para isomer will be 1,4-Dichlorobenzene. The reaction is given below

(ii) When Ethyl chloride, $$C{H}_{3}C{H}_{2}Cl$$ is treated with Silver Nitrite, $$AgN{O}_2$$it will lead to the formation of Nitroethane and white precipitate of Silver chloride, $$AgCl$$. This process is known as Victor Meyer Method.

(iii) When 2-bromopentane is treated with alcoholic KOH it will follow Saytzeff’s rule and will undergo $$\beta -$$ elimination. This reaction will give two products. Among that one will be major and the other will be minor. The major product in this reaction is Pent-2-ene and the minor product will be Pent-1-ene.

Therefore,
(i) When Chlorobenzene is treated with $$C{l}_2/FeC{l}_3$$, it will give 1,2-Dichlorobenzene and 1,4-Dichlorobenzene.
(ii) When Ethyl chloride is treated with $$AgN{O}_2$$, it will give Nitroethane.
(iii) When 2-bromopentane is treated with alcoholic KOH, it will give Pent-2-ene as the major product and Pent-1-ene as the minor product.

Note: According to the Saytzeff’s rule, when dehydrohalogenation reaction takes place and the most stable product will be that alkene i.e., 2-pentene, which has largely substituted alkene group in it. The less substituted alkene will be the minor product and also called the Hofmann product.