question_answer

If the relative reactivity of\[1{}^\circ ,\text{ }2{}^\circ \]and\[3{}^\circ \]hydrogens towards free radical chlorination is \[1:4.5:5.5,\]what would be the percentage of 1-chloro-2-methyl cyclohexane in the free radical chlorination of methyl cyclohexane?

A)  25%                      

B)  33.6%

C)  60%                      

D)  75%

Correct Answer: B

Solution :

                 

	H	Reactivity	Reactivity\[\times \]No.
\[1{}^\circ \]	3	1	3
\[2{}^\circ \]	10	4.5	45
\[3{}^\circ \]	1	5.5	5.5

Total = 53.5 Probability of formation of l-chloro-2-methyl cyclohexane is \[=\frac{45\times 2\times 100}{53.5\times 5}=33.6%\]