Phenolphthalein Solution 0.2%

Phenolphthalein Solution 0.2%

Phenolphthalein solution (0.2%) is a commonly used pH indicator in acid-base titrations. It is a colorless, clear solution that turns pink in basic solutions (typically above pH 8.2) and remains colorless in acidic environments. This concentration is typically prepared by dissolving phenolphthalein in ethanol or alcohol, then diluting with water.

Specifications:

• Chemical Name: Phenolphthalein

• Concentration: 0.2% w/v (0.2 g in 100 mL of solution)

• CAS Number: 77-09-8 (pure phenolphthalein)

• Solvent Base: Usually ethanol (95%) or isopropanol

• Appearance: Clear, colorless liquid

• pH Transition Range: pH 8.2 (colorless) to pH 10.0 (pink)

• Storage Conditions: Store in a tightly closed container, away from light and heat

Uses:

• Acid–Base Titrations: As a visual pH indicator to detect endpoint

• Educational Demonstrations: In chemistry labs for teaching pH concepts

• Soap Testing: In titration of fatty acids or saponification reactions

• Cleaning Validation: Sometimes used in pharmaceutical industry procedures

• Forensic Testing: Part of Kastle-Meyer test for blood (in alkaline form)

Features:

• ✅ Sharp color change – Makes endpoint detection easy in titrations

• ✅ Colorless to pink – Clear visual contrast around pH 8.2–10

• ✅ Simple preparation – Easily diluted from phenolphthalein powder

• ✅ Stable in alcohol solution – Long shelf life when properly stored

• ✅ Widely used in education and industry – Reliable and low-cost

• ⚠️ Flammable (ethanol base) – Keep away from open flames

• ⚠️ Mildly toxic if ingested – Use proper PPE and handle with care