How to prepare thymol blue solution for pH testing?

Thymol blue is a kind of pH indicator. Before using, add 0.04 g in 100 mL Ethanol (20%) or 0.04 g in 0.86 mL Sodium Hydroxide solution, dilute 0.1 mol/L and fill up to 100 mL with water. Its color changes from red to yellow between pH 1.2 and 2.8, and from yellow to blue between pH 8.0 and 9.6.

You may like