Used in analytical chemistry primarily as a standard for the standardization of EDTA solutions in complexometric titrations, providing a reliable source of calcium ions for accurate volumetric analysis. This is essential for determining water hardness (calcium and magnesium content) in water samples, as well as metal ion concentrations in industrial solutions and pharmaceutical formulations. Its high purity, solubility, and known concentration make it suitable for precise calibration in quality control laboratories, ensuring reliable validation of analytical methods.