Tags: Chemical Compound, Chemical Substance.
Bromothymol blue (also known as bromothymol sulfone phthalein Bromthymol Blue and BTB) is a pH indicator for weak acids and bases. It is mostly used in applications that require measuring substances that would have a relatively neutral pH (near 7) such as managing the pH of pools and fish tanks. A common use is for measuring the presence of carbonic acid in a liquid. It is typically sold in solid form as the sodium salt of the acid indicator.
