What will be the major organic product of the following reaction?
`C_(6)H_(5)C_(2)H_(5) underset((ii)NaCN)overset((i)Br_(2),hv)to`

Explanation

When ethylbenzene is treated with `Br_(2)` in presence of light, the bromine free radical formed during the reaction, abstracts the `alpha` (but not `beta`-) hydrogen from the ethyl group to form a resonance stabilized benzylic radical (I) which then reacts with `Br_(2)` to form 1-bromo-1-phenylethane (II). this on treatment with NaCN undergoes nucleophilic substitution to form 2-phenylpropanenitrile (III).