Hydrochloric Acid is a strong acid in terms of chemical ionization, and solutions of it can be assayed with a standardized solution of a strong base, such as Sodium Hydroxide. The endpoint can be determined potentiometrically or by using a pH indicator. The selection of the indicator used depends on the initial concentration of the Hydrochloric Acid and the strength of the alkali used. This is due to the fact that the Normalities of the acid and the base affect the shape of the neutralization curve that results during the titration.