Compare the stability of following carbocations.

Which of the following carbocations is most stable?

The stability order of the above carbocations is 

Arrange the following carbanions in order of their decreasing stability

(i) ${\mathrm{H}}_3\mathrm{C}-\mathrm{C}\equiv {\mathrm{C}}^{-}$

(ii) $\mathrm{H}-\mathrm{C}\equiv {\mathrm{C}}^{-}$

(iii) ${\mathrm{H}}_3\mathrm{C}-{\mathrm{CH}}_2^{-}$

The major products $\mathrm{A}$ and $\mathrm{B}$ in the following reactions are

Choose the correct statement regarding the formation of carbocations A and B given :-

 Arrange the following free radicals in order of decreasing stability:

$\mathrm{Methyl}\left(\mathrm{I}\right), \mathrm{Vinyl}\left(\mathrm{II}\right),\mathrm{Allyl}\left(\mathrm{III}\right) \mathrm{and} \mathrm{benzyl}\left(\mathrm{IV}\right)$

The correct order of stability of given carbocation is:

The decreasing order of the stability of the following carbocations is