Chemistry - GOC Question with Solution | TestHub

$\mathrm{C}-\mathrm{H}$ homolysis gives radicals, so compare radical stabilization rather than carbocations. The $\mathrm{H}$ in $\mathrm{III}$ is vinylic: removing it gives a high-energy vinylic radical and the largest bond-dissociation energy. IV gives an ordinary secondary radical; the benzene ring is separated from the radical by an ${\mathrm{sp}}^3$ carbon, so it is not a benzyl radical. $\mathrm{II}$ gives an allylic radical. $\mathrm{I}$ gives a radical delocalized over a longer conjugated diene system and has the smallest dissociation energy. Therefore $\mathrm{I}$ < $\mathrm{II}$ < IV < $\mathrm{III}$, A. The repeated distractor $\mathrm{D}$ has been replaced by a distinct false order.