Question

Choose the correct statement(s) for the given carbocation intermediate:
$RC{H}_2-\stackrel{+}{C}H-C{H}_2-Cl$

• A. $RC{H}_2$ group shows $-I$ effect and hence stabilizes the carbocation.
• B. $RC{H}_2$ group shows $+I$ effect and hence stabilizes the carbocation.
• C. $Cl$ group shows $-I$ effect and hence destabilizes the carbocation.
• D. $Cl$ group shows $+I$ effect and hence stabilizes the carbocation.

Answer 1

Answer: (B), (C)

$Cl$ group shows $-I$ effect and hence destabilizes the carbocation.

$RC{H}_2$ group is an electron donating group and hence it shows $+I$ effect. Since it is an electron donor, stability increases as overall positive charge reduces.
$Cl$ group is an electron withdrawing group and hence it shows $-I$ effect. Since it withdraws electrons, the overall positive charge on carbocation will increase and subsequently stability decreases.