Question

Explain the mechanism of addition of HBr to propene.

Answer 1

Step 1: 

Formation of electrophile: 

In HBr, br is more electronegative than H. When bonded electron move towards Br, polarity is developed and it creates electrophile H⁺ which attacks to the double bond to form a carbocation.

Step 2 :

Secondary carbonation is more stable than primary carbonation and it predominates over the primary carbonation.

Step 3 :

The Br^-1 ion attack the 2°- carbocation to form 2- Bromo propane as the major product.