2020 Phase-2 HydrocarbonsFree Radical Halogenation of Alkanes Medium Question 2 of 2 in Free Radical Halogenation of Alkanes

Which of the following is a free radical substitution reaction?

A Propene with $HBr/(C_6H_5COO)_2$
B Benzene with $Br_2/AlCl_3$
C Acetylene with HBr
D Methane with $Br_2/h\nu$

The answer is D.

Solution

Methane reacting with $Br_2$ in the presence of UV light ($h\nu$) proceeds via a free radical substitution mechanism (initiation, propagation, termination steps), replacing hydrogen atoms with bromine.

Concept Free radical halogenation of alkanes

Free Radical Halogenation of Alkanes in past papers

2 questions from this chapter have appeared across 2 exam years.