Question

Isopentane on monochlorination gives four isomeric monochloro derivatives of isopentane. Which product(s) has/have yield less than 35% in the mixture?

• A. 1-chloro-2-methylbutane
• B. 2-chloro-2-methylbutane
• C. 2-chloro-3-methylbutane
• D. 1-chloro-3-methylbutane

Answer 1

Answer: (A), (B), (D)

The correct options are
A 1-chloro-2-methylbutane
B 2-chloro-2-methylbutane
D 1-chloro-3-methylbutane

The probability factor for $3^0,2^{0}and{1}^{0}H$ atoms is 5.0 : 3.8 : 1.0 at ${25}^{0}C$ for chlorination.

% of 1-chloro-2-methylbutane = $\frac{6\times 1}{6+5+7.6+3}\times 100=27.8$%

% of 2-chloro-2-methylbutane = $\frac{1\times 5}{6+5+7.6+3}\times 100=23.15$%

% of 2-chloro-3-methylbutane = $\frac{2\times 3.8}{6+5+7.6+3}\times 100=35.18$%

% of 1-chloro-3-methylbutane = $\frac{3\times 1}{6+5+7.6+3}\times 100=13.89$%