Reaction of $HBr$ with propene in the presence of peroxide gives $n$-propyl bromide. This addition reaction is an example of anti-Markownikoff addition reaction.
(ie, it is completed in form of free radical addition.)
$CH_3 - CH = CH_2 + HBr {->[\text{Peroxide}]} \underset{\text{n - propyl bromide}}{CH_3 - CH_2 - CH_2Br}$
Mechanism of this reaction is represented as follows
Step 1 . formation of free radical of peroxide by means of decomposition.
$\underset{\text{Benzoyl peroxide}}{C_6H_5 - \underset{\overset{||}{O}}{C} - O -O - \underset{\overset{||}{O}}{C} - C_6H_5} {->[\Delta]} $$\underset{\text{Benzoate free radical}}{2C_6H_5 - CO\overset{\bullet}{O}}$
Step 2 . Benzoate free radical forms bromine free radical with $HBr$.
$C_6H_5CO\overset{\bullet}{O} + HBr \to C_6H_5COOH + \overset{\bullet}{Br}$
Step 3 . Bromine free radical attacks on $C =C$ of propene to form intermediate free radical.
Hence, $CH_3 - \overset{\bullet}{C}H-CH_2Br$ is the major product of this step.
Step 4 . More stable free radical accept hydrogen free radical from benzoic acid and give final product of reaction.
$CH_3 - \overset{\bullet}{C}H - CH_2Br+C_6H_5COOH \to \underset{\text{n-propyl bromide}}{CH_3-CH_2-CH_2Br+C_6H_5CO\overset{\bullet}{O}}$
Step 5. Benzoate free radicals are changed into benzoyl peroxide for the termination of free radical chain.
$C_6H_5CO\overset{\bullet}{O}+ C_6H_5CO\overset{\bullet}{O} \to (C_6H_5CO)_2O_2$
Hydrocarbons can be described asorganic compounds that consists only hydrogen and carbon atoms. These compounds are of different types and thereby have distinct natures. Hydrocarbons are colorless gases and are known for discharging faint odours. These have been categorized under four major classes named as alkynes,alkanes, alkenes, and aromatic hydrocarbons.
Types of Hydrocarbons
Saturated hydrocarbons - Saturated hydrocarbons are those compounds where there is a single bond exists between carbon atoms and are saturated with atoms of hydrogen.
Unsaturated hydrocarbons - Hydrocarbons comprises of at least one double or triple bond between carbon atoms are known as unsaturated hydrocarbons.
Aliphatic hydrocarbons - The term denotes the hydrocarbons formed as an outcome of the chemical degradation of fats.Aliphatic hydrocarbons are basically chemical compounds.
Aromatic hydrocarbons - They are distinguished because of the presence of benzene rings in them. They give away distinct types of aroma. These hydrocarbons comprises of only hydrogen and carbon atoms.
