---
title: "Formaldehyde Structure (CH2O): 3D Model, Formula & Molar Mass | MolDraw"
url: https://www.moldraw.com/molecules/formaldehyde.html
description: "Structure of Formaldehyde (CH2O, 30.03 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/) › Formaldehyde structure

# Formaldehyde structure and 3D model (CH2O)

Formaldehyde (methanal) is the simplest aldehyde: one carbon double-bonded to oxygen and bonded to two hydrogens.

**Quick answer:** Formaldehyde is **CH2O**, molar mass **30.03 g/mol**. Trigonal planar and polar; a gas that dissolves readily in water.

Atom labels Hydrogens Spin

Drag to rotate · pinch or scroll to zoom. 3D coordinates: computed with RDKit (ETKDG conformer, force-field optimised).

## Formaldehyde at a glance

| Formula | CH2O |
| --- | --- |
| Molar mass | 30.03 g/mol |
| IUPAC name | formaldehyde |
| Atoms / bonds | 4 / 3 |
| H-bond donors / acceptors | 0 / 1 |
| logP (estimated) | -0.2 |
| SMILES | `C=O` |
| InChIKey | `WSFSSNUMVMOOMR-UHFFFAOYSA-N` |
| PubChem | [712](https://pubchem.ncbi.nlm.nih.gov/compound/712) |

![2D structural formula of Formaldehyde (CH2O)](https://www.moldraw.com/molecules/img/formaldehyde.svg)

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

## What the 3D model of Formaldehyde shows

The model contains **4 atoms** (2 heavy atoms and 2 hydrogens) joined by **3 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 0 and accept 1 hydrogen bonds, and its estimated logP of -0.2 means it is very water-loving (hydrophilic). Its topological polar surface area is 17 Ų.

## Shape and bond angles

| Atom(s) | Geometry / hybridisation | Angles & lengths |
| --- | --- | --- |
| carbon | Trigonal planar, sp² | H–C–H ≈ 116°, H–C=O ≈ 122° |
| C=O bond | Double bond | ≈ 1.21 Å |

### Is Formaldehyde polar?

Yes. The C=O bond is polar and the flat, unsymmetrical shape gives a net dipole of about 2.3 D. In water it mostly turns into methanediol.

## Elemental composition of CH2O

| Element | Atoms | Mass (g/mol) | Mass % |
| --- | --- | --- | --- |
| Carbon (C) | 1 | 12.011 | 40.00% |
| Hydrogen (H) | 2 | 2.016 | 6.71% |
| Oxygen (O) | 1 | 15.999 | 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 formaldehyde

- Making resins for plywood, particleboard and insulation
- Formalin (about 37% in water) preserves biological specimens
- Building block for many chemicals and plastics

## Interesting facts

- Formaldehyde is a gas at room temperature, boiling at about −19 °C.
- It is made by oxidising methanol over a metal catalyst.
- It has been detected in interstellar space.

**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 Formaldehyde?

Formaldehyde (methanal) is the simplest aldehyde: one carbon double-bonded to oxygen and bonded to two hydrogens. Its SMILES is C=O.

### What shape is formaldehyde?

Trigonal planar. The carbon has three electron domains (two C–H bonds and one C=O) and no lone pairs.

### What is formalin?

A solution of formaldehyde in water, usually about 37%, often with some methanol to stop it polymerising.

### What is the chemical formula and molar mass of Formaldehyde?

Formaldehyde is CH2O with a molar mass of 30.03 g/mol. It contains 4 atoms: 1 carbon, 2 hydrogen, 1 oxygen.

### What is the IUPAC name of Formaldehyde?

The IUPAC name is formaldehyde.

### How do I draw Formaldehyde?

Open the MolDraw editor, paste the SMILES C=O or type "Formaldehyde" 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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