Question

What will be the ratio of 1,2 and 3 chloropentane if \( n \)-pentane is made to undergo chlorination? Assume that reactivity of all H-atoms is same. 

(1) \( 33.33 \% \) each 

(2) \( 16.67 \%: 33.33 \%: 50 \% \) 

(3) \( 25 \%: 25 \%: 50 \% \) 

(4) \( 50 \%: 33.33 \%: 16.67 \% \)

Answer 1

Correct option is (4) 50% : 33.33% : 16.67%

Since all hydrogen atom have same reactivity

\(\because\) In pentane , there are six hydrogen atom at 1 - position four Hydrogen atom at 2 - position and two Hydrogen at 3 - position

therefore, 1,2 and 3 chloropentane will be

form In the ratio

6 : 4 : 2

or 3 : 2 : 1

the percentage of 1 - chloropentane = \(\cfrac{100}6\) x 3 = 50%

The percentage 2 - chloropentane = \(\cfrac{100}6\) x 2 = 33.33%

The percentage 3 - chloropentane = \(\cfrac{100}6\) x 1 = 16.67%

Hence, The ratio of 1,2 and 3 chloropentane  will be 

50% : 33.33% : 16.67%