MOLECULAR POLARITYFIELD NOTE 94 / 175
Is CO polar or nonpolar?
CO is weakly polar, with an unusually small dipole whose negative end is on carbon.
Carbon Monoxide · linear
The molecule in space
Drag to turn the molecule. A two-atom molecule has no bond angle.
01 / MODEL RECORDPubChem 3D coordinates. Atom sizes and bond thickness are illustrative.How model data is used ↗
Why CO is polar
Carbon monoxide has different atoms at the two ends, so it has a permanent dipole. Its electron distribution is more subtle than a simple electronegativity comparison: the small measured dipole points toward carbon.
What to notice
CO is an exception to the simple rule that the negative end must lie on the more electronegative atom. Its small dipole has the negative end on carbon.
Common questions about CO
- 01
What does the Lewis structure of CO show?
A common Lewis structure is :C≡O: with one lone pair on each atom. In that formal-charge drawing, C is −1 and O is +1; its small measured dipole points toward C.
- 02
What is the molecular geometry of CO?
CO is a two-atom molecule, so its geometry is linear. A bond angle needs three atoms and is not defined here.
- 03
What is the molar mass of CO?
CO has an approximate molar mass of 28.01 g/mol, calculated from its formula using abridged standard atomic weights. Natural isotope variation can change the last digits.