Question

The addition of HBr to an alkene in the presence of peroxide is the example of

• A. electrophilic addition reaction
• B. nucleophilic addition reaction
• C. free radical addition reaction
• D. the formation of carbocation as an intermediate

Answer 1

Answer: (C)

Addition of HBr to an alkene in the presence of peroxide is the example of free radical addition reaction. $R-O-O-R\to 2R-O^{\bullet }$ $R-O^{\bullet }+HBr\to R-OH+B{r}^{\bullet }$ $R-CH=C{H}_2+B{r}^{\bullet }\to R-\stackrel{\bullet }{\mathrm{CH}}-C{H}_{2}Br$ $R-\stackrel{\bullet }{\mathrm{CH}}-C{H}_{2}Br\stackrel{HBr}{\to }RC{H}_{2}C{H}_{2}Br+B{r}^{\bullet }$ $B{r}^{\bullet }+B{r}^{\bullet }\to B{r}_2$