Question

Stability order of the following compounds is:

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

Answer 1

The correct option is A $\left(I\right)>\left(II\right)>\left(IV\right)>\left(III\right)$

$\text{Stability of carbocations}\propto \text{Number of}\alpha \text{-H}$

Structure $\left(I\right)$ has 6 $\alpha$-H, $\left(II\right)$ has 4 $\alpha$-H, $\left(III\right)$ has no $\alpha$-H, and $\left(IV\right)$ has 3 $\alpha$-H.
Therefore the correct order of stability of carbocations will be:
$\left(I\right)>\left(II\right)>\left(IV\right)>\left(III\right)$