Phenolphthalein

C₂₀H₁₄O₄

IUPAC: 3,3-Bis(4-hydroxyphenyl)-2-benzofuran-1(3H)-one

CAS: 77-09-8

Overview

Phenolphthalein is the most famous acid-base indicator, turning pink in basic solutions. It was also used as a laxative until concerns about carcinogenicity.

Composition

Element	Symbol	Atoms	Atomic Mass
Hydrogen	H	14	1.0080
Carbon	C	20	12.0110
Oxygen	O	4	15.9990

Elemental Composition

Hydrogen ×14

4.4%

Carbon ×20

75.5%

Oxygen ×4

20.1%

Uses

• Acid-base indicator
• Universal indicator component
• Historical laxative

Fun Facts

✦ The most commonly used acid-base indicator in chemistry education worldwide

Safety

⚠ Possible carcinogen
⚠ No longer used as laxative

Structure

SMILES

C1=CC=C2C(=C1)C(=O)OC2(C3=CC=C(C=C3)O)C4=CC=C(C=C4)O

Properties

Type: organic
State: solid
Molar Mass: 318.32 g/mol
Density: 1.2770 g/cm³
Melting Point: 262.5 °C
Solubility: insoluble

Molecular Descriptors

Exact Mass: 318.0892
XLogP: 3.6
TPSA: 66.8 Å²
H-Bond Donors: 2
H-Bond Acceptors: 4
Rotatable Bonds: 2
Heavy Atoms: 24
Complexity: 438.0

Related Compounds

1,2-Dichloroethane

C₂H₄Cl₂

1,3-Butadiene

C₄H₆

1,4-Dioxane

C₄H₈O₂

1-Butanol

C₄H₁₀O

2-Propanol

C₃H₈O

Acetaldehyde

CH₃CHO

Acetamide

C₂H₅NO

Acetic Anhydride

C₄H₆O₃

Acetone

(CH₃)₂CO

Acetonitrile

C₂H₃N

Frequently Asked Questions

What is Phenolphthalein?

Phenolphthalein (C₂₀H₁₄O₄) is a organic compound with the IUPAC name 3,3-Bis(4-hydroxyphenyl)-2-benzofuran-1(3H)-one.

What is the molecular weight of Phenolphthalein?

Phenolphthalein has a molar mass of 318.32 g/mol.

What state is Phenolphthalein at room temperature?

Phenolphthalein is a solid at room temperature.

Is Phenolphthalein organic or inorganic?

Phenolphthalein is classified as an organic compound.

What elements make up Phenolphthalein?

Phenolphthalein (C₂₀H₁₄O₄) is composed of Hydrogen (H), Carbon (C), Oxygen (O).