The electrophilic addition of hydrogen bromide HBr to propene C3H6 is a two-step reaction mechanism that involves the formation of a carbocation intermediate. The reaction proceeds as follows:Step 1: Protonation of the alkeneIn the first step, the alkene propene acts as a nucleophile and attacks the electrophilic hydrogen atom of HBr. This leads to the breaking of the H-Br bond, with the electrons moving towards the bromine atom. As a result, a carbocation intermediate is formed, and a bromide ion Br- is generated. According to Markovnikov's rule, the hydrogen atom will attach to the carbon with the least number of hydrogen atoms in this case, the central carbon , forming a secondary carbocation.Propene + HBr [CH3-CH + -CH3] + Br-Step 2: Nucleophilic attack by bromide ionIn the second step, the bromide ion Br- acts as a nucleophile and attacks the positively charged carbon atom of the carbocation intermediate. This leads to the formation of the final product, 2-bromopropane.[CH3-CH + -CH3] + Br- CH3-CH Br -CH3Stereochemistry of the product:The electrophilic addition of HBr to propene results in the formation of 2-bromopropane. Since the reaction occurs at a sp3 hybridized carbon atom, the product will be a chiral molecule. However, the reaction is not stereoselective, and both R and S enantiomers of 2-bromopropane will be formed in equal amounts, resulting in a racemic mixture.