3 In the
aqueous phase, the substituted ammonium cations get stabilised
not only by electron releasing effect of the alkyl group (+I) but also
by solvation with water molecules The greater the size of the ion,
lesser will be the solvation and the less stabilised is the ion The
order of stability of ions are as follows:
Decreasing order of  extent of H-bonding in water and order of
stability of ions by solvation