Carbon monoxide, a carbon oxide compound with the chemical formula CO and a molecular weight of 28.0101, is usually a colorless, odorless, and odorless gas.

In terms of physical properties, carbon monoxide has a melting point of -205 ℃ and a boiling point of -191.5 ℃. It is difficult to dissolve in water (with a solubility of 0.002838g in water at 20 ℃) and is not easy to liquefy and solidify.

In terms of chemical properties, carbon monoxide has both reducing and oxidizing properties, and can undergo oxidation reactions (combustion reactions), disproportionation reactions, etc; It is also toxic and can cause varying degrees of poisoning symptoms at high concentrations, endangering the brain, heart, liver, kidneys, lungs, and other tissues of the human body, and even electrocution like death. The minimum lethal concentration for inhalation is 5000ppm (5 minutes).

In industry, carbon monoxide is the foundation of one carbon chemistry and can be prepared by methods such as coke oxygen method. It is mainly used for the production of methanol and phosgene, as well as organic synthesis.