CO

Is colorless, odorless, tasteless, toxic gas, insoluble in water, melting point -199 ° C, boiling point -191.5 ° C. Under the standard condition, the gas density is L.25g /L, which is very different from the air density (1.293g/L under the standard condition), which is also one of the factors prone to gas poisoning. It is a neutral gas.