Concept:In presence of peroxide, HBr addition to alkene follows free radical mechanism (peroxide effect) via more stable radical intermediate.
Explanation:For
Ph−CH=CH2 (styrene) with peroxide,
Br∙ adds to terminal carbon
CH2, forming benzylic radical
Ph−C˙H−CH2Br, which is resonance-stabilized.
This radical abstracts H from HBr to give
Ph−CH2−CH2Br (1-bromo-2-phenylethane) as major product.
Statement A is true: reaction proceeds via more stable radical intermediate.
Statement B is false: peroxide does not generate
H∙; it generates radicals that ultimately produce
Br∙ (chain-carrying radical).
Statement C is true: benzoyl peroxide can form phenyl radicals
Ph∙, which abstract H from HBr forming benzene (
PhH) as byproduct.
Statement D is false: 1-bromo-2-phenylethane is the major product, not minor.
Statement E is true: in absence of peroxide, HBr adds by electrophilic addition via carbocation intermediate (benzylic carbocation), giving Markovnikov product.
Thus, correct statements are A, C, and E.
Answer:Option C (A, C & E Only)