Congo red
IUPAC: disodium;4-amino-3-[[4-[4-[(1-amino-4-sulfonatonaphthalen-2-yl)diazenyl]phenyl]phenyl]diazenyl]naphthalene-1-sulfonate
| Formula / Notation | C32H22N6Na2O6S2 |
|---|---|
| CAS Number | 573-58-0 |
| Molecular Weight | 696.7 |
| Also Known As | disodium;4-amino-3-[[4-[4-[(1-amino-4-sulfonatonaphthalen-2-yl)diazenyl]phenyl]phenyl]diazenyl]naphthalene-1-sulfonate; 573-58-0; DIRECT RED 28; C.I. Direct Red 28; Congazone sodium; Benzo Congo Red; Haemomedical; Haemonorm; Hemorrhagyl; Solucongo |
| Category | Indicators |
What is Congo red?
Congo Red is an indicator dye that is blue-violet at pH 3.0 and red at pH 5.0. It contains a 3,3'-(biphenyl-4,4'-diyldidiazene-2,1-diyl)bis(4-aminonaphthalene-1-sulfonate). It is functionally related to a 3,3'-(biphenyl-4,4'-diyldidiazene-2,1-diyl)bis(4-aminonaphthalene-1-sulfonic acid).
Formula & Notation
IUPAC Name: disodium;4-amino-3-[[4-[4-[(1-amino-4-sulfonatonaphthalen-2-yl)diazenyl]phenyl]phenyl]diazenyl]naphthalene-1-sulfonate
Other Names / Synonyms: disodium;4-amino-3-[[4-[4-[(1-amino-4-sulfonatonaphthalen-2-yl)diazenyl]phenyl]phenyl]diazenyl]naphthalene-1-sulfonate; 573-58-0; DIRECT RED 28; C.I. Direct Red 28; Congazone sodium; Benzo Congo Red; Haemomedical; Haemonorm; Hemorrhagyl; Solucongo
Properties & Characteristics
Uses & Applications
Safety Information
Always consult the SDS/MSDS before handling any chemical. This information is for educational purposes only.
Key Facts
Frequently Asked Questions
Congo Red is an indicator dye that is blue-violet at pH 3.0 and red at pH 5.0. It contains a 3,3'-(biphenyl-4,4'-diyldidiazene-2,1-diyl)bis(4-aminonaphthalene-1-sulfonate). It is functionally related to a 3,3'-(biphenyl-4,4'-diyldidiazene-2,1-diyl)bis(4-aminonaphthalene-1-sulfonic acid).
Used as a pH indicator in acid-base titrations, analytical chemistry, and chemical education demonstrations.
May be irritant or toxic in concentrated form. Handle with care. Consult SDS before use.
The formula or notation for Congo red is: C32H22N6Na2O6S2