Cresol red indicator solution

Cresol Red indicator solution is a dark red, aqueous acid-base indicator solution used primarily in titrations and pH measurements. The solution typically contains cresol red dye (o-cresolsulfonphthalein) dissolved in water or a water-alcohol mixture, and it exhibits color changes in specific pH ranges.​

Properties

Appearance: Dark red clear solution.

pH transition ranges:

Acidic range (pH 0.5–2.5): color changes from pink brownish to yellow.

Alkaline range (pH 6.5–8.5): color changes from yellow to purple.

Dye content in indicator grade is often about 95% purity.

Solubility: Miscible with water and soluble in ethanol or dilute acids and alkalis).​

Uses

Widely used as a pH indicator in acid-base titrations due to distinct color changes.

Useful in diagnostic assays and scientific research involving pH measurements or monitoring.

Employed in chemical manufacturing and analytical laboratories to visually detect pH shifts across moderate acidic and alkaline ranges.​

Storage and Handling

Store at room temperature in a tightly sealed container, protected from light to prevent dye degradation.

Handle with care as the dye may cause skin or eye irritation.​

For catalog description: “Cresol Red indicator solution, dark red clear liquid, pH range 0.5–2.5 (pink to yellow) and 6.5–8.5 (yellow to purple), dye content ~95%, used for pH determination in titrations and assays.”​