The total of all forms of acidity, including mineral acidity, carbon dioxide, and acid salts in a solution. Total acidity is usually determined by titration with a standard base solution to the phenolphthalein endpoint (pH 8.3). (See acidity.)
Amount of both weak and strong acids in water, usually expressed in milliequivalents of a strong base necessary to neutralize one liter of a water sample, using methyl-red or phenolphthalein as an indicator.