Halogenation is a substitution reaction, where halogen replaces one or more hydrogens of hydrocarbon.

Chlorine free radical make `1^(@), 2^(@), 3^(@)` radicals with almost equal ease, whereas bromine free radicals have a clear preference for the formation of tertiary free radicals. So, bromine is less reactive, and more slective whereas chlorine is less selective and more reactive.
The relative rate of abstraction of hydrogen by Br is
`{:(3^(@),gt,2^(@),gt,1^(@)),((1600),,(82),,(1)):}`
The relative rate of abstraction of hydrogen by Cl is
`{:(3^(@),gt,2^(@),gt,1^(@)),((5),,(3.8),,(1)):}`
Which of the following will give five monochloro prodcuts, when allowed to react with `Cl_(2)` in presence of sun light (excluding stereoisomers) ?

Options

A. n-pentane
B. Iso-pentane
C. 2-methyl-pentane
D. 3-methyl pentane

Answer

C

Explanation

1. `CH_(3) - underset(CH_(3))underset(|)(CH) - CH_(2) - CH_(2) - CH_(2) - Cl`
2. `CH_(3) - underset(CH_(3))underset(|)(CH) - CH_(2) - overset(Cl)overset(|)(CH) - CH_(3)`
3. `Cl - CH_(2) - underset(CH_(3))underset(|)(CH) - CH_(2) - CH_(2) - CH_(3)`
4. `CH_(3) - underset(CH_(3))underset(|)(CH) - overset(Cl)overset(|)(CH) - CH_(2) - CH_(3)`
5. `CH_(3) - underset(CH_(3))underset(|)overset(Cl)overset(|)(C) - CH_(2) - CH_(2) - CH_(3)`