(i) The Bronsted - Lowery theory can be extended to acid - base reactions in non-aqueous solvents. It can be used in differentiating the acid strength of a particular acid and in titration of weak bases.
(ii) In water solvent, mineral acids appear to be equally strong because of their complete ionisation, water is called here a leveling solvent because it levels all the acids to the same strength.
(iii) If instead of water solvent, we take mineral acids in pure acetic acid solvent (which is poor proton acceptor as compared to water) it is found acids become weak and can be differentiated.
Ex:
In above example acetic acid and Cl– ions both compete for protons and the former being a poor proton acceptor does it much less effectively than water. Thus HCl in acetic acid solvent appears to be a much weaker acid than that in water.
(iv) Mineral acids in acetic acid solvent follow the following order of their strengths.
HNO3 < HCl < H2SO4 < HBr < HClO4
v) A weak base like acetamide or acetanilide in aqueous medium can not be titrated with acids. If how ever, the weak base is taken in glacial acetic acid solvent, the former behaves as a strong base and can be titrated. This is because acetic acid (which acts as a better proton donor) exerts a leveling effect on the base.
