Class 11 NEET Chemistry Hydrocarbons Questions

Bromine naturally exist in liquid phase and in question bromine is given in gaseous phase.
Br2(l)

∆

––––––>

Br2(g)
Reaction take place at high temperature so mechanism with Br2(g) should be free radical substitution which can take place in propene and butane.
Rate of free radical substitution reaction depend upon stability of free radical

Propenyl free radical more stable so answer will be C3H8