Acid-base titrations - Types of titrations

While the strength of an acid is determined along with the help of a standard solution of base, it is termed as acidimetry. Similarly, when the strength of a base (alkali) is determined along with the help of a standard solution of an acid, it is termed as alkalimetry.  Both of these titrations include neutralisation of an acid with an alkali. In these titrations H⁺ ions of the acid combine with OH^- ions of the alkali to form unionised molecules of water.

The end point in these titrations is ascertained by the make use of organic dyes that are either weak acids or weak bases. These change their colours in a limited range of hydrogen ion concentrations, that is,pH of the solution. Phenolphthalein is a suitable indicator in the titrations of strong alkalies (free from carbonate) in opposition to strong acids or weak acids. Methyl orange is work as an indicator in the titrations of strong acids against strong and weak alkalies. Like no indicator gives correct results in the titrations of weak acids against weak bases, such titrations are carried out by some other methods (physical methods).