Order of reactivity of hydrogen halides (HX) with propene is,
CH3−CH=CH2+HX⟶CH3−
C
|
X
H−CH3
Reaction type is electrophilic addition. When propene treated with HX, it form propyl halide. Reactivity of HX is HI>HBr>HCl>HF due to presence of weak bonding in HI, it is more reactive towards this reaction.