Total Alkalinity (m-value) of Water by Endpoint Titration

The pH of the water is the measure of its alkalinity and is measured by its capacity to neutralize acid. The 'm' in the m-value stands for methyl orange which is used as an indicator for pH 4. Although the technique used is potentiometric, the term is used in general for stating the alkalinity of water. The alkalinity of water is mainly due to the salts of carbonate, bicarbonate present.

This application is used to determine the total alkalinity (m-value) of various water samples by titration with HCl. The titration is monitored by potentiometric measurementwith a pH sensor and terminated at an endpoint (EP) of pH 4.3.