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Bromination reaction- It is the addition of Bromine atoms to the carbon atoms
across double/triple bond of an unsaturated hydrocarbon to form the corresponding
saturated derivative [Bromo Alkane].
 Bromination of Ethene to 1,2 diBromoEthane-

H 2C=CH 2 + Br 2H2BrC-CBrH 2
Ethene 1,2- dibromo Ethane

 Bromination of Ethyne to 1,1,2,2- tetra bromo Ethane-
This reaction takes place in 2 steps, where there is an addition of 2 molecules of
Bromine across the C≡C bond.
Step-1 HC≡CH + Br 2H2BrC=CBrH 2
Ethyne 1,2- dibromo Ethene

Step-2 H2BrC=CBrH 2 + Br 2HBr 2C-CBr 2H
1,2- dibromo Ethene 1,1,2,2 – tetra bromo Ethane

 Bromination reaction- is used as a test to identify the presence of
unsaturated hydrocarbons.
Bromine is reddish brown in colour.
 When it is added to an alkane [saturated hydrocarbon], the reddish brown
colour of bromine does not change.
Reason- There is no addition reaction between an Alkane and bromine.

 When it is added to an alkene/alkyne [unsaturated hydrocarbon], the reddish
brown colour of bromine gets discharged.
Reason- Addition reaction takes place when Bromine is added to an unsaturated
hydrocarbonto form the corresponding Bromo derivative, which is acolorless
compound..

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