Acids induce salivation in the mouth which increases the bicarbonate secretions thus the sour taste. Sour taste receptors detect the hydrogen ion in the acids.
Acids may react with the fluids in the eye and thus irritate the eye cells. This is because they alter the pH of the eye fluids. Once they get into the eye they should be rinsed thoroughly with enough water and professional medical assistance sought.
Bases have a soapy feel in the skin. This is because they dissolve the fatty acids in the skin and form complexes. These complexes have a slippery feel.
The bases taste bitter in the mouth. The OH ions bind to the bitter taste receptors thus causing the bitter taste.
Once these bases get into the eyes, they alter pH of eye fluids thus causing irritation.
