The higher the number of alkaline groups, the greater the charge is the deflection and hence the more carbonium ion is permanent.

$ -\mathrm{OCH}_3,-\mathrm{NO}_2,-\mathrm{CN},-\mathrm{CH}_3-\mathrm{NHCOCH}_3,$ $ -\mathrm{COR},-\mathrm{OH},-\mathrm{COOH},-\mathrm{Cl}$


