Final answer:
Hydrohalogenation of a symmetrical alkene results in the formation of a monosubstituted alkyl halide, such as chloroethane from ethene through the addition of a hydrogen halide.
Step-by-step explanation:
Hydrohalogenation of a symmetrical alkene involves the addition of a hydrogen halide, such as hydrochloric acid, to the double bond of the alkene, resulting in a monosubstituted alkyl halide. For instance, the hydrohalogenation of ethene (a symmetrical alkene) using hydrogen chloride (HCl) leads to the formation of chloroethane. This reaction is an example of an electrophilic addition reaction where the electrophilic hydrogen of the hydrogen halide attaches to one of the carbon atoms of the double bond, while the halide ion, in this case, chloride, attaches to the other carbon atom.
Learning Objectives
To understand the addition reactions of alkenes with hydrogen, halogens, and water, such as the formation of chloroethane through hydrohalogenation, it is crucial to recognize this as a straightforward method to convert alkenes into alkyl halides. The product of such a reaction maintains the same carbon skeleton as the original alkene.