Carbon dioxide was discovered by Von Helmont and was isolated by Joseph Black in 1757. Physical properties of carbon dioxide were shown by Yandell Henderson in 1925 and J S Haldane in 1926.
It was frequently used to stimulate respiration and there was provision for carbon dioxide cylinders on old Boyle’s machines.
It is commercially produced by the action of heat or, calcium or magnesium carbonate in the preparation of their oxides.
One of the important physical properties of carbon dioxide is that it is colourless gas with pungent odour in high concentration. Molecular weight is 44 and specific gravity is 1500. It is 0.03% in the atmosphere and 4% in the expired air. It is non-inflammable and does not support combustion.
It is kept in liquid state in gray cylinders at a pressure of 733 pi. The cylinders are mounted vertically like nitrous oxide and cyclopropane.
Other physical properties of carbon dioxide include:
– Critical temperature is 31°C
– Critical pressure is 73.8 bar
– Density is 1.87 kg/ccc at 15°C