Question

In the bromination and chlorination of alkanes, which carbon atoms in the alkane structure are generally the most reactive? a) primary b) secondary c) tertiary d) quaternary

Answer 1

Bromination or chlorination of alkanes occur through the formation of a radical intermediate by abstraction of hydrogen radical attached to the carbon atom by the chlorine or bromine free radical. Greater is the stability of the radical intermediate, higher is the reactivity. Since tertiary radical is most stable, the most reactive carbon atom is the tertiary carbon atom.

Hence, the correct option is (c).

Note: Quaternary carbon atoms has no hydrogens attached to be abstracted by the chlorine or bromine radical to result a radical intermediate. Hence, it does not react.