Titration is a technique to measure the concentration of an acid or alkali in a sample, by comparing it to the concentration of an alkali or acid in a standard solution.

A retort stand has a metal clamp attached near the top of the pole. The metal clamp is holding a burette. A conical flask sits on the base of the retort stand below the burette. Label 1 points at the burette to filled with a standard solution. Label 2 points at the metal clamp holding the burette. Label 3 points at the conical flask which contains a solution of unknown concentration and indicator.

Figure: Titration apparatus. 1: The burette is filled with a standard solution; 2: A clamp holds the burette; 3: The flask contains a solution of unknown concentration and indicator.