• Alkenes?will react readily with?hydrogen halides?such as?HCl?and?HBr?to produce?halogenoalkanes
• This reaction is known as?hydrohalogenation?
• It is also an?electrophilic addition?reaction that occurs quickly at room temperature

Hydrohalogenation reactions in alkenes

• All the?hydrogen halides?react in this way, but the?fastest reaction?occurs in the order?HI > HBr > HCl?due to the increasing bond strength of the hydrogen-halogen bond, so the weakest bond reacts most easily
• The mechanism of this reaction is part of Higher Level Chemistry and is covered in Section 20