Acid-base titrations

The titration of an acid solution with a standard solution of alkali will determine the amount of alkali which is equivalent to the amount of acid present (or vice versa). The point at which this occurs is called the equivalence point or end-point. For example, the titration of hydrochloric acid with sodium hydroxide can be expressed as follows:


If both the acid and alkali are strong electrolytes, the resultant solution will be neutral (pH 7). If on the other hand either the acid or alkali is a weak electrolyte the resultant solution will be slightly alkaline or acidic, respectively. In either case, detection of the end-point requires accurate measurement of pH. This can be achieved either by using an indicator dye, or by measuring the pH with a glass electrode.