Task: Text Categorization
Input (English): This substance is dissolved in alcohol, then placed on concrete, in a test to measure carbonation depth. The peroxidase-catalyzed oxidation of this molecule provides the basis for the Kastle-Meyer test. It was replaced by bisacodyl in the laxative Correctol shortly before FDA reports confirmed its carcinogenicity. This molecule's most notable property occurs due to interconversion between a lactone structure and one containing a quinoid ring. It is synthesized by reacting phenol molecules with phthalic anhydride in the presence of hot sulfuric acid. For 10 points, name this "universal indicator" that is colorless in acidic solution and pink or purple in basic solution.
Output (English): Science