vapour density การใช้

• Air is given a vapour density of one.
• For example, acetone has a vapour density of 2 in relation to air.
• Hofmann also developed a method for determining the molecular weights of liquids from vapour densities.
• During this time he also determined the vapour density from Tin ( II ) chloride and Sulphur.
• Dumas used the method to determine the vapour densities of elements ( mercury, phosphorus, sulfur ) and inorganic compounds.
• With this definition, the vapour density would indicate whether a gas is denser ( greater than one ) or less dense ( less than one ) than air.
• In many web sources, particularly in relation to safety considerations at commercial and industrial facilities in the U . S ., vapour density is defined with respect to air, not hydrogen.
• For this use, air has a molecular weight of 28.97 atomic mass units, and all other gas and vapour molecular weights are divided by this number to derive their vapour density.
• From 8 July 1891 he was a professor of chemistry at the University of Greifswald and from 1897 succeeded as the Chair of the Department of Inorganic Chemistry at the University of Kiel where he continued his research on the determination of vapour density.
• Cannizzaro showed how the atomic weights of elements contained in volatile compounds can be deduced from the molecular weights of those compounds, and how the atomic weights of elements of whose compounds the vapour densities are unknown can be determined from a knowledge of their specific heats.
• In an 1826 paper, he described his method for ascertaining vapour densities, and the redeterminations which he undertook by its aid of the atomic weights of carbon and oxygen proved the forerunners of a long series which included some thirty of the elements, the results being mostly published in 1858 1860.