MolDraw › 3D molecule models › Lactic acid structure
Lactic acid structure and 3D model (C3H6O3)
Lactic acid is a three-carbon carboxylic acid with an OH group on the middle carbon. That carbon is a stereocentre, so it exists as L and D forms.
Drag to rotate · pinch or scroll to zoom. 3D coordinates: computed with RDKit (ETKDG conformer, force-field optimised).
Lactic acid at a glance
| Formula | C3H6O3 |
|---|---|
| Molar mass | 90.08 g/mol |
| IUPAC name | 2-hydroxypropanoic acid |
| Atoms / bonds | 12 / 11 |
| H-bond donors / acceptors | 2 / 2 |
| logP (estimated) | -0.5 |
| SMILES | CC(C(=O)O)O |
| InChIKey | JVTAAEKCZFNVCJ-UHFFFAOYSA-N |
| PubChem | 612 |
What the 3D model of Lactic acid shows
The model contains 12 atoms (6 heavy atoms and 6 hydrogens) joined by 11 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 2 and accept 2 hydrogen bonds, and its estimated logP of -0.5 means it is very water-loving (hydrophilic). Its topological polar surface area is 58 Ų.
Shape and bond angles
| Atom(s) | Geometry / hybridisation | Angles & lengths |
|---|---|---|
| C2 (CH–OH) | Tetrahedral, sp³; stereocentre | ≈ 109.5° |
| carboxyl carbon | Trigonal planar, sp² | ≈ 120° |
| methyl carbon | Tetrahedral, sp³ | ≈ 109.5° |
Is Lactic acid polar?
Yes. The OH and COOH groups make it very polar, and it mixes with water in all proportions.
Elemental composition of C3H6O3
| Element | Atoms | Mass (g/mol) | Mass % |
|---|---|---|---|
| Carbon (C) | 3 | 36.033 | 40.00% |
| Hydrogen (H) | 6 | 6.048 | 6.71% |
| Oxygen (O) | 3 | 47.997 | 53.28% |
Calculated from IUPAC standard atomic weights. Check any formula with the molar mass calculator.
Uses of lactic acid
- Made from glucose in muscles when oxygen is low
- Food acidulant and preservative (E270), and the sour taste in yogurt
- Monomer for the biodegradable plastic PLA (polylactic acid)
Interesting facts
- Lactic acid was first isolated from sour milk by Carl Wilhelm Scheele in 1780.
- Muscles mainly make L-lactic acid, the (S) form.
- Lactate is no longer thought to be the main cause of muscle soreness a day or two after exercise.
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Open MolDraw editorFrequently asked questions
What is the structure of Lactic acid?
Lactic acid is a three-carbon carboxylic acid with an OH group on the middle carbon. That carbon is a stereocentre, so it exists as L and D forms. Its SMILES is CC(C(=O)O)O.
Is lactic acid chiral?
Yes. C2 carries H, OH, CH₃ and COOH, so there are two enantiomers. Commercial lactic acid is often a racemic mix.
Is lactic acid a strong acid?
No. It is a weak acid with a pKa of about 3.9, a little stronger than acetic acid because of the nearby OH group.
What is the chemical formula and molar mass of Lactic acid?
Lactic acid is C3H6O3 with a molar mass of 90.08 g/mol. It contains 12 atoms: 3 carbon, 6 hydrogen, 3 oxygen.
What is the IUPAC name of Lactic acid?
The IUPAC name is 2-hydroxypropanoic acid.
How do I draw Lactic acid?
Open the MolDraw editor, paste the SMILES CC(C(=O)O)O or type "Lactic acid" in name search, and the structure is drawn for you. You can then export it as PNG, SVG, MOL or CDXML.