Conductometry is the measurement of the electrical conductivity of a solution to determine the concentration of dissolved ions in the solution. It is a widely used analytical technique in the fields of chemistry, biochemistry, and environmental science to determine the ionic composition, acidity or basicity, and purity of various substances. Conductometry is based on the fact that the electrical conductivity of a solution is directly proportional to the concentration of ions in the solution.
In conductometric analysis, an electrical current is passed through a sample solution, and the voltage across the electrodes is measured. The conductivity of the solution is then calculated from the current and voltage readings. The conductance is directly proportional to the concentration of ions in the solution, and this relationship is described by the Kohlrausch law.
Conductometric measurements require accurate calibration of the conductivity cell and the use of standardized solutions of known concentration. Various types of electrodes are used in conductometry, including platinum electrodes, silver electrodes, and glass electrodes.
There are two types of conductometric titration methods: direct and indirect. In the direct method, the titrant is added to the sample solution until the conductivity reaches a maximum, indicating the endpoint of the titration. In the indirect method, a solution of the titrant reacts with the sample solution to form a product with a different conductivity, which is then measured to determine the endpoint of the titration.
The advantages of conductometry include its high sensitivity, fast analysis time, and low cost. It is also a non-destructive analysis technique that does not require expensive equipment. However, conductometric analysis may be affected by temperature, electrode contamination, and interference from other ions in the solution. Therefore, careful calibration and quality control are essential to achieve accurate and reliable results.