When carbon burns in air that has little
oxygen in it, the gas carbon monoxide is formed. It is formed, for
instance, when the engine of an automobile runs in a closed garage.
In
carbon monoxide there is only one atom of oxygen for every atom of
carbon. The chemist's formula for it is CO. It will grab up more oxygen
whenever it has a chance. Many people have died from breathing carbon
monoxide. The gas is very poisonous because it keeps the blood from
carrying oxygen.
But this dangerous gas can be useful, too. It can
be used to take oxygen from places where it is not wanted. Most iron
ore, for example, has oxygen in it. Carbon monoxide can be used to take
the oxygen from the ore and leave only the iron.
