Bromthymol blue

Bromthymol Blue is a pH indicator used for measuring the pH of a solution. It is a weak acid that can be used in a variety of scientific and medical applications.

Chemical Properties

Bromthymol blue is a chemical compound with the formula C₂₇H₂₈Br₂O₅S. It appears as a greenish-blue crystalline powder at room temperature and is soluble in water and alcohol. The compound is a weak acid, which means it can donate a proton (H⁺) in a chemical reaction.

Usage

Bromthymol blue is most commonly used as a pH indicator. In this role, it changes color depending on the pH of the solution it is in. At a pH below 6.0, bromthymol blue is yellow. Between pH 6.0 and 7.6, it transitions from yellow to blue. Above pH 7.6, it is blue. This makes it useful for determining the pH of a solution within this range.

In addition to its use as a pH indicator, bromthymol blue is also used in medical and scientific research. For example, it is used in respiration experiments to indicate the presence of carbon dioxide, which lowers the pH of a solution and causes the bromthymol blue to change color.

Safety

While bromthymol blue is generally safe to handle, it can cause irritation if it comes into contact with the skin or eyes. It can also be harmful if swallowed or inhaled. Therefore, it should be handled with care, and appropriate safety measures should be taken when using it in a laboratory setting.

See Also

• pH indicator
• Acid-base titration
• Chemical compound
• Respiration