Dimethyl yellow indicator solution

Dimethyl yellow indicator solution is typically prepared as a 0.2% (w/v) solution of dimethyl yellow dye dissolved in 90% ethanol. This solution is used as a pH indicator where it shows a color change from red at pH below 2.9 to yellow at pH above 4.0, suitable for titrations involving weak bases and strong acids.

To prepare this solution, dissolve 0.2 grams of dimethyl yellow powder in 100 mL of 90% ethanol, ensuring complete dissolution. The solution should be stored in a tightly closed container, protected from light and moisture to maintain stability and performance.

This indicator solution is commonly used in laboratory acid-base titrations and is valued for its sharp color change within the acidic pH range, helping accurately detect endpoints.​

In summary:

Concentration: 0.2% w/v dimethyl yellow in 90% ethanol

Color change: Red below pH 2.9, yellow above pH 4.0

Storage: Tightly sealed, protected from light and moisture

Application: Acid-base titrations involving weak bases and strong acids

This approach ensures reliable and reproducible pH indication in analytical procedures.