Bromthymol Blue

**Semantic type:** Indicator, Reagent, or Diagnostic Aid|Organic Chemical

**Definition:** A dye used as an indicator in determining pH. Bromthymol blue is a weak acid. It can be in acid or base form, depending on the pH of the solution. This reagent is yellow in acidic solutions, blue in basic solutions and green in neutral solution.

**Synonyms:** - 4,4'-(3H-2,1-Benzoxathiol-3-ylidene)bis(2-bromo-3-methyl-6-(1-met-hylethyl)phenol) S,S-dioxide - BROMTHYMOL BLUE - Bromothymol Blue - Dibromothymolsulfophthalein