MolDraw › 3D molecule models › Citric acid 3D model
Citric acid molecule model (C6H8O7)
Citric acid is a tricarboxylic acid with three COOH groups and one OH on a five-carbon backbone. It gives lemons their sour taste and is central to the citric acid (Krebs) cycle.
Drag to rotate · pinch or scroll to zoom. 3D coordinates: PubChem conformer (CID 311).
Citric acid at a glance
| Formula | C6H8O7 |
|---|---|
| Molar mass | 192.12 g/mol |
| IUPAC name | 2-hydroxypropane-1,2,3-tricarboxylic acid |
| Atoms / bonds | 21 / 20 |
| H-bond donors / acceptors | 4 / 7 |
| XLogP3 | -1.7 |
| SMILES | C(C(=O)O)C(CC(=O)O)(C(=O)O)O |
| PubChem CID | 311 |
What the 3D model of Citric acid shows
The model contains 21 atoms (13 heavy atoms and 8 hydrogens) joined by 20 bonds; in ball-and-stick mode every stick is one bond, and double or aromatic bonds are drawn as multiple sticks. Switch to space-filling to see the molecule as its electron cloud, scaled to van der Waals radii: this is the shape other molecules actually "feel". It can donate 4 and accept 7 hydrogen bonds, and its PubChem XLogP3 of -1.7 means it is very water-loving (hydrophilic). Its topological polar surface area is 132 Ų.
Shape and bond angles
| Atom(s) | Geometry / hybridisation | Angles & lengths |
|---|---|---|
| central C3 | Tetrahedral, sp³ | ≈ 109.5° |
| carboxyl C (×3) | Trigonal planar, sp² | ≈ 120° |
Is Citric acid polar?
Very polar: three acid groups and one OH make it highly water-soluble.
Elemental composition of C6H8O7
| Element | Atoms | Mass (g/mol) | Mass % |
|---|---|---|---|
| Carbon (C) | 6 | 72.066 | 37.51% |
| Hydrogen (H) | 8 | 8.064 | 4.20% |
| Oxygen (O) | 7 | 111.993 | 58.29% |
Calculated from IUPAC standard atomic weights. Check any formula with the molar mass calculator.
Uses of citric acid
- Food acidulant and preservative (E330)
- Chelating agent in cleaners and descalers
- Buffer in drinks, cosmetics and medicines
Interesting facts
- Citric acid is triprotic with pKa values of about 3.13, 4.76 and 6.40.
- Lemon and lime juice contain about 5–6% citric acid.
- Its anion, citrate, is the first intermediate in the Krebs cycle.
Drawing structures for your notes? MolDraw is a free online chemical structure editor for molecules, reactions and lab diagrams.
Open MolDraw editorFrequently asked questions
How many acidic hydrogens does citric acid have?
Three, one per carboxyl group (pKa ≈ 3.1, 4.8 and 6.4). The OH hydrogen is not acidic in water.
Is citric acid chiral?
No. Its central carbon carries two identical CH₂COOH groups, so it is achiral.
What is the chemical formula and molar mass of citric acid?
Citric acid is C6H8O7 with a molar mass of 192.12 g/mol (PubChem CID 311). It contains 21 atoms: 6 carbon, 8 hydrogen, 7 oxygen.
What is the IUPAC name of Citric acid?
The PubChem-computed IUPAC name is 2-hydroxypropane-1,2,3-tricarboxylic acid.
How do I make a model of Citric acid?
Rotate the interactive model above to see how its 21 atoms connect, then copy it with a ball-and-stick kit: use the CPK colours shown (carbon grey or black, hydrogen white, oxygen red, nitrogen blue). For a school project, foam balls and toothpicks work well.