C

Citric acid

IUPAC: 2-hydroxypropane-1,2,3-tricarboxylic acid

C6H8O7 Acids CAS 77-92-9
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Quick Reference
Formula / NotationC6H8O7
CAS Number77-92-9
Molecular Weight192.12
Melting Point307 °F (anhydrous) (NTP, 1992)
Boiling PointDecomposes (NTP, 1992)
Density1.54 at 68 °F (USCG, 1999) - Denser than water; will sink
Solubilitygreater than or equal to 100 mg/mL at 72 °F (NTP, 1992)
AppearanceCitric acid appears as colorless, odorless crystals with an acid taste. Denser than water. (USCG, 1999)
Also Known As2-hydroxypropane-1,2,3-tricarboxylic acid; 77-92-9; Citric acid, anhydrous; Aciletten; Anhydrous citric acid; Citro; Citretten; Citric acid anhydrous; Chemfill; Hydrocerol A
CategoryAcids

What is Citric acid?

Citric acid is a tricarboxylic acid that is propane-1,2,3-tricarboxylic acid bearing a hydroxy substituent at position 2. It is an important metabolite in the pathway of all aerobic organisms. It has a role as a calcium chelator, an antimicrobial agent, a chelator, a food acidity regulator and a fundamental metabolite. It is a conjugate acid of a citrate anion and a citrate(1-).

Formula & Notation

C6H8O7

IUPAC Name: 2-hydroxypropane-1,2,3-tricarboxylic acid

Other Names / Synonyms: 2-hydroxypropane-1,2,3-tricarboxylic acid; 77-92-9; Citric acid, anhydrous; Aciletten; Anhydrous citric acid; Citro; Citretten; Citric acid anhydrous; Chemfill; Hydrocerol A

Properties & Characteristics

Appearance: Citric acid appears as colorless, odorless crystals with an acid taste. Denser than water. (USCG, 1999). Molecular formula: C6H8O7. Molecular weight: 192.12 g/mol. Boiling point: Decomposes (NTP, 1992). Melting point: 307 °F (anhydrous) (NTP, 1992). Density: 1.54 at 68 °F (USCG, 1999) - Denser than water; will sink. Solubility: greater than or equal to 100 mg/mL at 72 °F (NTP, 1992). LogP: -1.7.

Physical Data

PropertyValue
Melting Point307 °F (anhydrous) (NTP, 1992)
Boiling PointDecomposes (NTP, 1992)
Density1.54 at 68 °F (USCG, 1999) - Denser than water; will sink
Molecular Weight192.12
Solubilitygreater than or equal to 100 mg/mL at 72 °F (NTP, 1992)
AppearanceCitric acid appears as colorless, odorless crystals with an acid taste. Denser than water. (USCG, 1999)

Uses & Applications

Used in industrial chemical synthesis, fertilizer production, battery electrolytes, metal processing, and laboratory acid-base reactions.

Safety Information

Corrosive. Causes severe burns to skin, eyes, and respiratory tract. Wear appropriate PPE including gloves, goggles, and lab coat. Consult SDS before use.

Always consult the SDS/MSDS before handling any chemical. This information is for educational purposes only.

Key Facts

Term Citric acid
Formula C6H8O7
CAS Number 77-92-9
Molecular Weight 192.12
Category Acids
Synonyms 2-hydroxypropane-1,2,3-tricarboxylic acid; 77-92-9; Citric acid, anhydrous; Aciletten; Anhydrous citric acid; Citro; Citretten; Citric acid anhydrous; Chemfill; Hydrocerol A

Frequently Asked Questions

Citric acid is a tricarboxylic acid that is propane-1,2,3-tricarboxylic acid bearing a hydroxy substituent at position 2. It is an important metabolite in the pathway of all aerobic organisms. It has a role as a calcium chelator, an antimicrobial agent, a chelator, a food acidity regulator and a fundamental metabolite. It is a conjugate acid of a citrate anion and a citrate(1-).

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Editorial standards: Chemical data is sourced from peer-reviewed literature, CAS Registry, NIST WebBook, and PubChem. Safety information reflects guidance from OSHA, ECHA, and IAEA. For educational purposes only — always consult official SDS documentation and qualified professionals before handling chemicals.