The density of a particular gas or vapour relative to that of hydrogen at the same pressure and temperature.
〔化〕蒸气密度，气密度
Example sentencesExamples
This legitimated the use of vapour densities for the determination of relative molecular weights.
Being much shorter than the height of the atmosphere, the laboratory cell would necessitate a correspondingly greater vapor density.
Even though, during the nineteenth century the science of chemistry was at a relatively early state, Dumas was able to show that the vapor densities of some organic compounds are directly proportional to their molecular weights.