Used as a pH indicator in acid-base titrations, particularly for strong acid-strong base reactions. It changes color from red in acidic solutions (pH below 3.1) to yellow in basic solutions (pH above 4.4), with an orange transition around pH 4.0. Commonly used in laboratories to determine the endpoint in neutralization reactions. Also applied in educational settings for teaching acid-base chemistry due to its clear and distinct color change. Suitable for testing water quality and in some industrial processes where approximate pH range detection is sufficient.