Thymol blue, also known as thymolsulfonphthalein, is a type of sulfomephthalein dye. It is a crystalline powder that is brownish-green or reddish-brown in colour and is insoluble in water. However, it is soluble in alcohol and in solutions of dilute alkali.
|Name of Product||Thymol Blue|
|Synonyms||Thymolsulfonephthalein; Thymolsulfophthalein; Sodium thymol blue; Azul Timol; Timolo blu; Thymol Bleu; Thymolblau|
|Molecular Weight||466.6 g/mol|
|1||Appearance (Form)||Solid powder|
|2||Appearance (Color)||Brownish-Green crystals|
|3||Melting point||221-224 °C (dec.) (lit.)|
|5||Solubility|| Insoluble in water;
Gives clear solution in 0.1% ethanol;
|6||UV-vis (λmax)|| 594 nm (1st)
376 nm (2nd)
|7||Storage temp.||Room temp.|
Q. What is the purpose of Thymol Blue?
Thymol Blue is used as a pH indicator to detect the acidity or basicity of solutions.
Q. Is Thymol blue the same as Bromothymol blue?
Bromothymol blue is produced by adding elemental bromine to Thymol blue in glacial acetic acid solution.
Q. How does thymol blue indicator works?
An aqueous solution of thymol blue undergoes the color changes from red to yellow in an acid solution (pKa ≈ 1.6) and from yellow to blue in an alkaline solution (pKa ≈ 8.9), thus functioning as a pH indicator.
Q. What colour is thymol blue in neutral?