China Phenolphthalein CAS 77-09-8 - China Suppliers & Factory for High-Quality Acid-Base Indicator Factories, Products

Chemical Name: Phenolphthalein, CAS No.: 77-09-8, Molecular Formula: C6H12O3, Molecular Weight: 318.32, Appearance: White crystalline powder, Sample: Free samples available, Solubility: Soluble in ethanol and diethyl ether; practically insoluble in water, Characteristics: Phenolphthalein is a well-known acid-base indicator that turns pink/purple-red in alkaline solutions while remaining colorless in neutral and acidic conditions. As a leading supplier in China, our factory offers high-quality phenolphthalein to meet diverse laboratory and industrial needs. Explore our free sample options and discover the exceptional reliability of our products from a trusted China supplier

Product Description

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℃
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 than 0.001%
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% (C₂₀H₁₄O₄)
Microorganism TPC < 1000 cfu/g
Y and M < 100 cfu/g
E-coli – Absent
Staphylococcus Aureus – Absent
Pseudomonas Aeruginosa – Absent
Albicans Saccharomyces – Absent
Application
Acid-Base Indicator
pH 8.2 – 10.0

Widely used in chemical experiments, water quality testing, and industrial titration analysis.

Color Change: Colorless in acidic → Colorless in neutral → Pink/Purple-red in alkaline solutions.

Pharmaceutical Uses
Pharmaceutical Raw Material

Historically used as a stimulant laxative to stimulate colonic mucosa and promote peristalsis.

Currently primarily used as a pharmaceutical raw material and research reagent, with clinical usage significantly reduced.

Industrial & Laboratory
Analytical Reagent

Serves as an analytical reagent and titration indicator.

Used for pH indication in the electroplating industry, as well as in teaching experiments and chemical detection kits.

Package
Standard Packaging 25 kg / Drum
Storage
Storage Conditions Store in a cool, dry place.
Frequently Asked Questions
Q1 What is the purity specification of this product?
The assay specification is 98.0%–101.0% (C₂₀H₁₄O₄), ensuring high-purity pharmaceutical and analytical grade quality.
Q2 What is the pH transition range when used as an acid-base indicator?
The transition range is pH 8.2 to 10.0. The color changes from colorless in acidic and neutral conditions to pink/purple-red in alkaline solutions.
Q3 What are the main industrial and laboratory applications?
It is used as an analytical reagent, titration indicator, and pH indicator in the electroplating industry. It is also widely applied in teaching experiments and chemical detection kits.
Q4 What are the standard packaging and storage requirements?
The product is packaged in 25 kg drums. It should be stored in a cool, dry place to maintain product stability and quality.
Q5 What microbiological standards does this product meet?
The product meets strict microbiological standards: TPC < 1000 cfu/g, Yeast & Mold < 100 cfu/g, and is confirmed absent for E-coli, Staphylococcus Aureus, Pseudomonas Aeruginosa, and Albicans Saccharomyces.
Q6 What are the physical characteristics of this product?
It appears as a white or almost white powder, practically insoluble in water but soluble in alcohol. Its melting point is approximately 260℃.

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