 The base should have a p"K"a value not less than about 4 log units smaller, or the equilibrium will lie almost completely to the left.The hydroxide ion by itself is not a strong enough base, but it can be converted in one by adding sodium hydroxide to ethanol
to produce the ethoxide ion.The pKa for self-dissociation of ethanol is about 16, so the alkoxide ion is a strong enough base.