Acids, with their large amount of hydrogen ions, have an acidic, or sour, taste. Vinegar and grapefruit juice are two harmless acids. Hydrochloric acid is much more dangerous and may cause severe burns.
Bases, or alkaline solutions, have a greater number of negative hydroxide ions. They have a slippery feel, like soap does, and are also characterized by a bitter taste. The addition of a base will decrease the acidity of a solution
Salts and water are formed when an acid and base are combined and neutralized. The negative ions of the base and the acid form water and the positive ions form a salt compound.