Question

Arrange the following compounds in increasing order of reactivity towards the addition of HBr RCH = CHR, `C`H_(2)` =`C`H_(2)`, `R_(2)`C = CHR, `R_(2)` = `C`R_(2)`
A. `CH_(2)=CH_(2) lt RCH =CHR lt R_(2)C=CHR lt R_(2)C=CR_(2)`
B. `R_(2)C=CHR lt RCH=CHR lt CH_(2)=CH_(2)lt R_(2)C=CR_(2)`
C. `RCH=CHR lt R_(2)C=CR_(2) lt R_(2)C=CHR lt CH_(2)=CH_(2)`
D. `R_(2)C=CR_(2) lt CH_(2)=CH_(2) lt RCH=CHR lt R_(2)C=CHR`

Answer 1

Correct Answer - A
Alkyl group increases the electron densityat the double bond by +1 effect. This is turn increses the reactivity towards electrophilic reaction which alkenes undergo with HBr. Therefore option A is corre.