Used as a pH indicator in analytical chemistry, particularly in titrations involving weak acids and strong bases. It changes color in the pH range of approximately 3.7 to 5.2, shifting from yellow to blue, making it suitable for detecting the endpoint in specific acid-base reactions. Commonly applied in water analysis and industrial quality control to determine acid content in solutions. Its solubility in water ensures uniform distribution in aqueous samples, enhancing accuracy in color change observation.