If air gets into fermentation mixture, the
oxygen of air oxidises ethanol to ethanoic acid which in turn destroys
the taste of alcoholic drinks Ethanol is a colourless liquid with boiling point 351 K It is used
as a solvent in paint industry and in the preparation of a number of
carbon compounds The commercial alcohol is made unfit for drinking
by mixing in it some copper sulphate (to give it a colour) and pyridine
(a foul smelling liquid)