Properties: white or light yellow triclinic fine crystal, tasteless, stable in air. 1g is soluble in 12ml ethanol and about 100ml ether, dark red in dilute alkali solution, very slightly soluble in chloroform, almost insoluble in water.

Molecular formula: C20H14O4

Melting point: 262.5 ° C

Density: 1.227 g/cm after (32 ° C)

Boiling point: 548.7 ℃ at 760 mmHg

Vapor pressure: 7.12 e-13 mmHg at 25 ℃

Solubility: < 0.1g / 100ml

Oil-water distribution coefficient: log Kow = 2.41

Dissociation constant: pKa = 9.7 (25 ℃)

Refractive index: 1.57 (7.9 C)

Stability: stability. Incompatible with strong oxidizing agents and bases.

Storage conditions: keep sealed in a cool, dry and windy area away from incompatible substances.

Phenolphthalein is colorless in acidic and neutral solutions, purplish red in alkaline solutions, orange in extremely acidic solutions, and colorless in extremely alkaline solutions.

When heated to decomposition, it gives off pungent and irritating fumes.

Phenolphthalein is a chemical that is a crystalline powder that is almost insoluble in water. It is colorless in acidic and neutral solutions and purplish red in alkaline solutions. It's often used to detect acids and bases. Phenolphthalein is a stimulant used in chronic constipation. Can directly stimulate the intestinal mucosa or activate the nerve endings of the intestinal smooth muscle and increase the intestinal propulsion. Excessive diarrhea leads to fluid and electrolyte disturbances. Long-term use can damage the enteric nervous system and may be irreversible.