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

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.