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Inorganic Chemistry

Carbon Monoxide

Definition and meaning of Carbon Monoxide in chemistry.

Carbon monoxide (CO) is a colorless, odorless, highly toxic gas produced by the incomplete combustion of carbon-based fuels, such as gasoline, wood, or natural gas, when oxygen supply is limited.

In more detail

The molecule consists of one carbon atom and one oxygen atom joined by a triple bond, making it isoelectronic with N2 and giving it an unusually short, strong bond. CO is dangerous to living organisms because it binds to the iron in hemoglobin about 200 times more tightly than oxygen does, forming carboxyhemoglobin and preventing red blood cells from delivering oxygen to tissues. Despite its toxicity, CO is an important industrial reagent and a ligand in coordination chemistry, where it forms metal carbonyl complexes.

Key facts

FieldInorganic Chemistry
Chemical FormulaCO
Molar Mass28.01 g/mol
BondingCarbon-oxygen triple bond; isoelectronic with N2
Example

A car engine running in a closed garage produces carbon monoxide from incomplete combustion of gasoline; because CO has no color or smell, it can accumulate to dangerous levels without detection, which is why CO detectors are used in homes.

Frequently asked questions

Why is carbon monoxide dangerous even at low concentrations?

Because it binds hemoglobin roughly 200 times more strongly than oxygen, even small amounts of CO can tie up a large fraction of the blood's oxygen-carrying capacity, leading to hypoxia in tissues and organs.

How does carbon monoxide differ from carbon dioxide?

Carbon monoxide (CO) has one oxygen atom and forms from incomplete combustion, whereas carbon dioxide (CO2) has two oxygen atoms and forms from complete combustion; CO is toxic and flammable, while CO2 is comparatively inert and non-toxic at typical concentrations.

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