ABSTRACT
Alkalinity of water is a measure of its acid-neutralizing ability. The titrable bases that contribute to the total alkalinity of a sample are generally the hydroxides, carbonates, and bicarbonates. However, other bases such as phosphates, borates, and silicates can also contribute to the total alkalinity. The alkalinity value depends on the pH end point designated in the titration. Alkalinity may also be determined by potentiometric titration to the preselected pH. In this titration, a standard acid titrant is added to a measured volume of sample aliquot in small increments of 0.5 mL or less, that would cause a change in pH of 0.2 unit or less per increment. The solution is stirred after each addition and the pH is recorded when a constant reading is obtained. A titration curve is constructed, plotting pH versus cumulative volume titrant added. The volume of titrant required to produce the specific pH is read from the titration curve.
