Base (substance)

In chemistry, any compound that in water solution is slippery to the touch, tastes bitter, turns red litmus paper blue, reacts with acids to form salts, and promotes certain chemical reactions called "base catalysis." Examples of bases are the hydroxides of the alkali and alkaline earth metals (sodium, calcium, etc.) and the water solutions of ammonia or its organic derivatives (amines). Such substances produce hydroxide ions (OH-) in water solutions. Bases yield hydroxyl ions when dissolved in water.