Sodium hydrogen phthalate half-hydrate is widely used as a primary standard in acid-base titrations due to its high purity and stability. It is particularly valuable in calibrating pH meters and standardizing alkaline solutions like sodium hydroxide. In analytical chemistry, it serves as a reliable reference material for ensuring accurate measurements in various laboratory procedures. Additionally, it is employed in buffer solutions to maintain a stable pH environment in biochemical and industrial applications. Its consistent performance makes it a preferred choice in quality control and research settings.