In the presence of peroxide addition of HBr to propene takes place according to Anti-Markovnikov's rule but peroxide effect is not seen in the case of HCl and HI. Explain.

In the presence of peroxide addition of HBr to propene takes place acc

1.	In the presence of peroxide addition of HBr to propene takes place according to Anti-Markovnikov's rule but peroxide effect is not seen in the case of HCl and HI. Explain.
Answer» Solution :Peroxide effect proceeds via free radical chain me chains mass given below : (i) `C_(6)H_(5)-overset(O)overset(\|\|)(C)-O-O-overset(O)overset(\|\|)(C)-C_(6)H_(5) overset("Homolysis")RARR 2C_(6)H_(5)-overset(O)overset(\|\|)(C)-Orarr 2C_(6)H_(15)+2CO_(2)` (ii) `overset(.)(C_(6))H_(5)+H-Br overset("Homolysis")rarr C_(6)H_(5)+Br` (iii) (iv) Peroxide effect is observed only in the case of HBr and not seen incase of HI and HCl. This is due to the fact that the H-Cl bond is stronger than B-Br bond. ALSO, bond energy of H-Cl bond is higher than H-Br. H-Cl bond is not CLEAVED by the free radical where as the H-I bond is weaker and iodine free RADICALS combine to form iodine molecules.