230535 The correct order of the addition reaction rates of halogen acids with ethylene is
: The stability of hydrogen halides decreases down the group due to decrease in bond $(\mathrm{H}-\mathrm{X})$ dissociation energy. Hence, the addition of hydrogen halide with alkene will be $\mathrm{HI}>\mathrm{HBr}>\mathrm{HCl}>\mathrm{HF}$.
