Reactions of Alkenes with Strong Acids

Reactions of Alkenes:
Electrophilic Additions
H2 Pt(metal)

First we will look at the reaction of alkenes with STRONG acids. For an acid to be an effective enough electrophile for an alkene, the acid must be a strong one. The strong acids are the haloacids (HCl, HBr, HI) and peroxyacids (H2SO4, HNO3, HClO4). All of these acids have a pKa with a negative sign meaning that they effectively are more than 100% ionized when dissolved in a solvent. Thus, a strong acid, HA, can be viewed as H+ and A:-. The H+ is the elctrophile that makes the reaction work.