Titration curve

Titration curve is a graphical representation of the concentration of an analyte versus the volume of titrant added in a titration. It is a crucial tool in analytical chemistry used to determine the concentration of an unknown solution or to understand more about its chemical properties.

Overview

A titration curve is generated by plotting the pH of the solution as a function of the volume of added titrant. The curve typically has a sigmoidal shape, with the inflection point, known as the equivalence point, representing the volume at which the amount of titrant added is stoichiometrically equivalent to the amount of analyte in the sample.

Types of Titration Curves

There are several types of titration curves, each corresponding to a different type of titration:

• Acid-Base Titration Curves: These curves are used in acid-base titration, where the titrant is an acid or a base. The pH changes dramatically around the equivalence point, allowing for a precise determination of the end point of the titration.

• Redox Titration Curves: In redox titration, the titrant is a reducing or oxidizing agent. The potential of the solution, measured with a redox electrode, changes as the titrant is added.

• Complexometric Titration Curves: These curves are used in complexometric titration, where the titrant forms a complex with the analyte. The end point is detected by a change in color of the solution or by using an indicator.

Determination of Equivalence Point

The equivalence point of a titration curve is determined by using an indicator or a pH meter. The choice of indicator depends on the pH at the equivalence point. For pH meters, the equivalence point is determined by finding the maximum slope of the pH curve.

Applications

Titration curves are used in various fields such as chemistry, biochemistry, environmental science, and medicine. They are used to determine the concentration of a solution, to understand the chemical properties of a substance, and to monitor chemical reactions.