Definition

Noun: A synthetic chemical compound used primarily as a dye and as an acid-base indicator in laboratory chemistry. It changes color in response to the acidity or alkalinity (pH) of a solution.

Usage

This word is a highly specific scientific term. It is used almost exclusively in technical contexts such as chemistry, biochemistry, and laboratory analysis. * The experiment required adding a drop of tetrabromo-phenolsulfonephthalein to monitor the pH change. * The properties of tetrabromo-phenolsulfonephthalein make it suitable for certain titration procedures.

Advanced Usage

• As a reagent: The compound is valued for its precise color change at a specific pH range, making it a reliable reagent for indicating the endpoint in acid-base titrations.

Variants and Related Words

• Bromophenol blue: This is the common name for tetrabromo-phenolsulfonephthalein. It is far more frequently used in both written and spoken scientific English.
  • Example: "Bromophenol blue is often used as a tracking dye in agarose gel electrophoresis."

Synonyms

• Acid-base indicator
• pH indicator dye
• Bromophenol blue (common name)

Notes on Different Meanings

This term has only one specific meaning in modern English: it refers to the chemical compound defined above. It is not used in idiomatic or figurative language.

Noun

1. a dye used as an acid-base indicator