The electrophilic addition reaction of propene C3H6 and hydrochloric acid HCl involves the following steps:1. Formation of the electrophile:Hydrochloric acid HCl dissociates into H+ and Cl- ions. The H+ ion acts as an electrophile in this reaction.2. Nucleophilic attack by the alkene:Propene, which is an alkene, has a double bond between two carbon atoms. This double bond consists of a sigma bond and a pi bond. The pi bond has a high electron density, making it a nucleophile. The nucleophilic pi bond attacks the electrophilic H+ ion, forming a bond between one of the carbon atoms and the hydrogen atom. This results in the breaking of the pi bond.3. Formation of the carbocation intermediate:After the addition of the hydrogen atom, a carbocation intermediate is formed. The positive charge is located on the carbon atom that did not bond with the hydrogen atom. In the case of propene, a secondary carbocation is formed, as the positively charged carbon is bonded to two other carbon atoms.4. Attack by the nucleophile:The negatively charged chloride ion Cl- acts as a nucleophile and attacks the positively charged carbon atom in the carbocation intermediate. This leads to the formation of a new bond between the carbon atom and the chloride ion.5. Formation of the final product:The electrophilic addition reaction is now complete, and the final product is 2-chloropropane C3H7Cl , an alkyl halide.Overall, the mechanism of the electrophilic addition reaction of propene and hydrochloric acid can be summarized as follows:Propene + HCl 2-chloropropane