Arrange the following carbocation in order of decreasing order of their stability.

Question

Professor PC Thomas Classes · Answer

+M effect of $-\mathrm{NH}-\mathrm{CH}_3>+\mathrm{M}$ of $-\mathrm{O}-\mathrm{CH}_3$ group disperse the charge of carbocation, hence increases the stability $-\mathrm{CH}_3$ group +HC and +IE so it will disperse the charge loss than $-\mathrm{NH}-\mathrm{CH}_3,-\mathrm{O}-\mathrm{CH}_3$ group. Whereas $-\mathrm{NO}_2$ group show - M and -1 effect due to which positive charge on the carbocation increases, hence stability decreases.