Phenolphthalein Quick Details

Chemical Name: Phenolphthalein

Synonyms: 3,3-Bis(4-hydroxyphenyl)phthalide

CAS No.: 77-09-8

Molecular Formula: C20H14O4

Chemical Structure: Phenolphthalein Structure

Molecular weight: 318.32

Appearance: A white powder, practically insoluble in water, soluble in alcohol.

Assay: 98.0%-101.0%

Phenolphthalein Typical Properties

Item	Specifications
Characteristics	A white or almost white powder, practically insoluble in water, soluble in alcohol.
Melting Point	It melts at about 260℃
Density	1.299 g/cm3
PH Color Change Range	8.2-10
Identification	A: Positive B: Positive
Appearance of solution	The solution is clear and not more intensely colored than reference solution Y7
Related substances	Less than 0.5%
Heavy metals	Not more than0.001%
Acidity or alkalinity	Complies
Chlorides	Not more than 0.01%
Sulphates	Not more than 0.02%
Loss on drying	Not more than 0.5%
Sulphated ash	Not more than 0.1%
Assay	98.0%-101.0%
Microorganism	TPC<1000cfu/g
	Y and M <100cfu/g
	E-coli – absent
	Staphylococcus Aureus-Absent
	Pseudomonas Aeruginosa-Absent
	Albicans Saccharomyces-Absent

Phenolphthalein Usage

Laboratory Analysis & Titration:
- Acid-Base Indicator: Standard pH indicator widely used in analytical laboratories for titration of weak acids with strong bases.
- pH Test Solutions & Papers: Used to formulate phenolphthalein indicator solutions and test papers for rapid alkalinity detection.
Construction & Civil Engineering:
- Concrete Carbonation Testing: Sprayed onto freshly fractured concrete surfaces to measure carbonation depth; uncarbonated alkaline concrete turns pink/magenta, while carbonated layers remain colorless.

Phenolphthalein Packaging and Shipping

Fiber Drum, 25kg

Phenolphthalein Storage

Keep container tightly sealed in a cool, dry, dark, and well-ventilated dedicated hazardous chemical warehouse.

Protect strictly from direct sunlight, ambient heat, and contact with strong oxidizers or strong bases.

Keep away from food and feed.

Phenolphthalein CAS 77-09-8