Bromocresol green

Bromocresol green is a dye of the triphenylmethane family and is used as a pH indicator in various laboratory and industrial applications. It is also known by its chemical name, 3,3',5,5'-tetrabromo-m-cresolsulfonphthalein.

Chemical Properties

Bromocresol green has the chemical formula C21H14Br4O5S and a molecular weight of 698.01 g/mol. It appears as a yellow powder and is soluble in ethanol and slightly soluble in water. The dye changes color depending on the pH of the solution it is in, making it useful for pH determination.

pH Indicator

Bromocresol green is commonly used as a pH indicator in titrations and other chemical analyses. It transitions from yellow to blue over a pH range of 3.8 to 5.4. Below pH 3.8, the dye appears yellow, and above pH 5.4, it appears blue.

Applications

Bromocresol green is used in various applications, including:

• Clinical chemistry: It is used in the measurement of serum albumin.
• Microbiology: It is used in culture media to identify microorganisms based on their ability to produce acid.
• Environmental testing: It is used to monitor pH levels in water and soil samples.

Safety and Handling

Bromocresol green should be handled with care, as it can be harmful if ingested or inhaled. Appropriate personal protective equipment (PPE) such as gloves and safety goggles should be worn when handling the dye.

See Also

• pH indicator
• Titration
• Clinical chemistry
• Microbiology
• Environmental testing