The electrophilic addition of hydrogen bromide HBr to propene C3H6 is an example of a reaction that proceeds via a Markovnikov addition mechanism. The reaction mechanism involves the following steps:1. Protonation of the alkene: The alkene propene acts as a nucleophile and attacks the electrophilic hydrogen atom of HBr. This results in the breaking of the H-Br bond and the formation of a carbocation intermediate. The most stable carbocation is formed, which in this case is the secondary carbocation CH3-CH + -CH3 .2. Nucleophilic attack by bromide ion: The bromide ion Br- that was generated in the first step acts as a nucleophile and attacks the carbocation, forming a new C-Br bond.The major product of this reaction is 2-bromopropane CH3-CHBr-CH3 , which is formed according to Markovnikov's rule. This rule states that in the addition of a hydrogen halide to an alkene, the hydrogen atom will add to the carbon with the greater number of hydrogen atoms, and the halide will add to the carbon with the fewer number of hydrogen atoms.The minor product, 1-bromopropane CH2Br-CH2-CH3 , can also be formed via a less stable primary carbocation intermediate, but this pathway is less favored due to the lower stability of the primary carbocation compared to the secondary carbocation.In summary, the reaction mechanism for the electrophilic addition of HBr to propene involves the protonation of the alkene to form a carbocation intermediate, followed by nucleophilic attack by the bromide ion. The major product is 2-bromopropane, and the minor product is 1-bromopropane.