MolDraw › 3D molecule models › 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.
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 |
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.
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.
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Open MolDraw editorFrequently 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.