A substance is analyzed to determine its qualitative and quantitative chemical composition. Thus, chemical analysis can be categorized as qualitative analysis and quantitative analysis. Two methods are adopted for determining the number of chemical substances in solution: titrimetric analysis and gravimetric analysis. Titrimetric analysis involves only volume measurement, whereas gravimetric analysis involves the measurement of volume and mass.

Titrimetric analysis helps determine the volume of a solution of accurately known concentration required to react quantitatively with the measured volume of a substance whose concentration is to be determined. The standard solution is a solution with an accurately known concentration.

The volume of the standard solution used, the chemical equation, and the relative molecular masses of the reacting compounds are used to calculate the mass of the substance dissolved in the solution of unknown concentration. The reagent of known concentration is known as titrant. Whereas the substance being titrated is known as the titrate.

Detection of endpoint

The endpoint is detected by a physical change in the reaction mixture or by adding an auxiliary reagent known as an indicator; alternatively, some other physical measurement may be used. On completion of the reaction, the indicator detects a change in the solution being titrated, such as a change in colour or turbidity.

In an ideal titration, the visible endpoint coincides with the stoichiometric or theoretical endpoint; however, a small difference usually occurs in practice, known as titration error.

The indicator and experimental conditions should be chosen so that the difference between the visible and theoretical endpoints is as small as possible.

Acidity and Alkalimetry
Titrimetric analysis can be carried out for various types of reactions. In this unit, you will learn only about neutralization reactions. These involve titrations of acids and bases. Standard solutions of acids (acidimetry) and bases (alkalimetry) are used in these titrations. The concentration of the solution is expressed in terms of molarity. It is the number of moles of solute dissolved in 1 litre of solution.

Standard Solution
A solution of exactly known concentration is called a standard solution. To prepare a standard solution, any substance that is stable at room temperature and does not react with the solvent in which it is dissolved can be directly weighed.

Watch this video to learn more about chemistry.