Acetic acid vs Citric acid: what is the difference?
Acetic acid has one acid group and is the sour and smell of vinegar, while citric acid has three, is an odourless solid and binds metal ions well.
Sources and notes
- The sentence under the titlefrom sourceMoleculeFinder comparison notesThe pair's answer line.
- The two drawingscomputedMoleculeFinder rule (RDKit MCS)Each molecule's own drawing, as its page shows it. The common core, 4 of 13 atoms, is too small to align on.
Side by side
| Acetic acid | Citric acid | |
|---|---|---|
| Molecular weightCalculated PubChem | 60.05 g/molC2H4O2 | 192.12 g/molC6H8O7 |
| Hydrogen-bond donorsCalculated PubChem | 1 | 4 |
| Where each turns upEditorial MoleculeFinder food and product lists |
|
Also on our fruit and household cleaners lists |
| FamilyEditorial MoleculeFinder curated | Organic acids | Organic acids |
| Everyday groupEditorial MoleculeFinder curated | Food & flavor | Food & flavor |
| Chemical groupsCalculated Found by rule (RDKit) | Carboxylic Acids | Alcohols, Carboxylic Acids |
| Hazard labelReported ECHA, EU CLP Regulation, Safe Work Australia, HSDB via PubChem; ECHA, EU CLP Regulation, Safe Work Australia via PubChem | Danger | Warning |
| The supplier-filed hazard label's signal word, not a statement about ordinary use. | ||
| Oral LD50Measured HSDB via PubChem | 3,530 mg/kgpure acetic acid, rat, oral | 3,000 mg/kgpure citric acid, rat, oral |
| A single acute animal measure. It ranks nothing about human safety. | ||
Sources and notes
- Molecular weightcomputedPubChemComputed from the structure; the formula is under each weight.
- Hydrogen-bond donorscomputedPubChemThe hydrogens on nitrogen or oxygen that each molecule can lend to a hydrogen bond, counted from its structure.
- Where each turns upfrom sourceMoleculeFinder food and product listsEach amount is an editorial figure from our lists, not a measurement of any one product. Each mark is set by hand on the list, never inferred.
- Familyfrom sourceMoleculeFinder curated
- Everyday groupfrom sourceMoleculeFinder curated
- Chemical groupscomputedFound by rule (RDKit)Each group is found in the structure by a chemical pattern.
- Hazard labelfrom sourceECHA, EU CLP Regulation, Safe Work Australia, HSDB via PubChem; ECHA, EU CLP Regulation, Safe Work Australia via PubChem
- Oral LD50from sourceHSDB via PubChem
- ECHAfrom sourceAttributionSource: European Chemicals Agency, echa.europa.eu.
- EU CLP Regulationfrom sourceAttributionSource: EUR-Lex, Regulation (EC) No 1272/2008, © European Union.
- Safe Work Australiafrom sourceAttributionSource: Safe Work Australia, Hazardous Chemical Information System, © Commonwealth of Australia, CC BY 4.0.
- Identifiersfrom sourcePubChemPubChem CID 176 (Acetic acid) and 311 (Citric acid).
In more detail
Both are the sour in a kitchen and they behave differently because of how many acid groups each carries. Acetic acid has one carboxylic acid group and is the whole of vinegar's sourness and smell, volatile enough to fill a room. Citric acid has three, is a solid crystal, and has no smell at all, which is why lemon-flavoured products use citric acid for the sour and something else for the aroma. Those three groups also make citric acid a good chelator, binding metal ions, which is why it descales a kettle better than vinegar does. Citric acid is far heavier at 192.12 against 60.05, and it is a real intermediate in the citric acid cycle that every aerobic cell runs.
Sources and notes
- The paragraphfrom sourceMoleculeFinder comparison notes
Questions
- What is the difference between Acetic acid and Citric acid?
- Acetic acid has one acid group and is the sour and smell of vinegar, while citric acid has three, is an odourless solid and binds metal ions well.
- Is Acetic acid bigger than Citric acid?
- Citric acid is the heavier molecule, 192.12 g/mol against 60.05 g/mol for Acetic acid. Acetic acid is C2H4O2 and Citric acid is C6H8O7.
- Which has the lower reported LD50, Acetic acid or Citric acid?
- Citric acid, at 3,000 mg/kg (oral, rat), against 3,530 mg/kg (oral, rat) for Acetic acid. An LD50 is one acute animal measurement, and the two here were not necessarily measured in the same species, so it is a data point rather than a ranking of how dangerous either is to a person.
Sources and notes
- The answersfrom sourceMoleculeFinderThe first is the pair's answer line; the others are read off the table above.