Ketone rule
The carbonyl carbon is bonded to two carbon groups.
This distinguishes acetone from aldehydes.
Molecular compound · ketone
Acetone
C₃H₆O
Acetone is C₃H₆O with structure CH₃–C(=O)–CH₃. The central carbonyl group makes the molecule polar and makes oxygen a strong hydrogen-bond acceptor.
Name note: acetone and propanone name the same compound.
Essentials
The central C=O group defines acetone as a ketone.
The carbonyl carbon is attached to carbon on both sides.
Detail
A 2D structure fixes the connectivity and carbonyl geometry.
The C=O bond is strongly polar and the carbonyl carbon is electron-poor relative to oxygen.
Polarity
Acetone has a permanent molecular dipole.
The carbonyl contribution is not canceled by symmetry.
Understand
Acetone accepts hydrogen bonds from water.
The carbonyl oxygen can accept a hydrogen bond, but acetone lacks O–H or N–H groups and is not a conventional donor.
Water mixing
The polar carbonyl interacts strongly with water.
Acetone is small enough that these interactions strongly influence miscibility.
Reference identifiers
Names and identifiers that pin down the chemical identity.
| Formula | C₃H₆O |
|---|---|
| CAS Registry Number | 67-64-1 |
| PubChem CID | 180 |
Advanced
Push past the first model without losing the simple picture.
Can acetone hydrogen-bond with itself?
It can accept but lacks the usual donor group, so it does not build the same donor–acceptor network as water.
Is C₃H₆O unique to acetone?
No. Molecular formula alone does not encode connectivity.
Why is carbonyl carbon electrophilic?
C=O polarization leaves carbonyl carbon electron-poor relative to oxygen.
Constituent elements