Question

Sort the following according to increasing order of the stability of carbocation.

• A. $(C{H}_3{)}_3{C}^{+}$
• B. $(C{H}_3{)}_{2}H{C}^{+}$
• C. $\left(C{H}_3\right)H_2{C}^{+}$
• D. $H_3{C}^{+}$

Answer 1

Stability of carbocation $\propto$ no. of $\alpha$-hydrogen
$(C{H}_3{)}_3{C}^{+}\to 9\alpha -H$
$(C{H}_3{)}_{2}H{C}^{+}\to 6\alpha -H$
$\left(C{H}_3\right)H_2{C}^{+}\to 3\alpha -H$
$C{H}_3^{+}\to Zero\alpha -H$
stability order
$(C{H}_3{)}_3{C}^{+}>(C{H}_3{)}_{2}H{C}^{+}>\left(C{H}_3\right)H_2{C}^{+}>H_3{C}^{+}$