Question:
The intermediate carbocation formed in the reactions of HI, HBr and HCl with propane is the same and the bond energy of HCl, HBr and HI is 430.5 kJ mol-1, 363.7 kJ mol-1 and 296.8 kJ mol-1 respectively. What will be the order of reactivity of these halogen acids?
Solution:
HI >HBr>HCl is the increasing order of reactivity. The increasing order of reactivity of halogen is same as their increase in bond energies.