---
title: "Lactic acid Structure (C3H6O3): 3D Model, Formula & Molar Mass | MolDraw"
url: https://www.moldraw.com/molecules/lactic-acid.html
description: "Structure of Lactic acid (C3H6O3, 90.08 g/mol): rotatable 3D model, 2D skeletal formula, IUPAC name, SMILES, shape, polarity, uses and FAQ."
lang: en
publisher: Scidart Academy
generated: 2026-10-26
---
[MolDraw](https://www.moldraw.com/) › [3D molecule models](https://www.moldraw.com/molecules/) › 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.

**Quick answer:** Lactic acid is **C3H6O3**, molar mass **90.08 g/mol**. Small and polar; miscible with water.

Atom labels Hydrogens Spin

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](https://pubchem.ncbi.nlm.nih.gov/compound/612) |

![2D structural formula of Lactic acid (C3H6O3)](https://www.moldraw.com/molecules/img/lactic-acid.svg)

2D structure (skeletal formula) · [Draw it in MolDraw](https://www.moldraw.com/)

## 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](https://www.moldraw.com/tools/free-chem-tools/molar-mass-calculator.html).

## 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.

**Drawing structures for your notes?** MolDraw is a free online chemical structure editor for molecules, reactions and lab diagrams.

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## Frequently 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.

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