Question

Arrange the following carbocations according their stability order.
$\left(I\right)C_{6}H_{5}\overset{+}{C}H_{2} \, \left(II\right) \, C_{6}H_{5}\left(CH\right)_{2}\overset{+}{C}H_{2}$
$\left(III\right) \, C_{6}H_{5}\overset{+}{C}\left(HCH\right)_{3}\left(IV\right) \, C_{6}H_{5}\overset{+}{C}\left(\left(CH\right)_{3}\right)_{2}$

• A. $\left(\right.II\left.\right) < \left(\right.I\left.\right) < \left(\right.III\left.\right) < \left(\right.IV\left.\right)$
• B. $\left(\right.I\left.\right) < \left(\right.II\left.\right) < \left(\right.III\left.\right) < \left(\right.IV\left.\right)$
• C. $\left(\right.III\left.\right) < \left(\right.II\left.\right) < \left(\right.I\left.\right) < \left(\right.IV\left.\right)$
• D. $\left(\right.IV\left.\right) < \left(\right.I\left.\right) < \left(\right.III\left.\right) < \left(\right.I\left.\right)$

Answer 1

Answer: (A)

Resonance and inductive effect decide stability of carbocations.

∴ Correct order of stability is
$\left(\right.II\left.\right) < \left(\right.I\left.\right) < \left(\right.III\left.\right) < \left(\right.IV\left.\right)$