抄録
A theoretical relation between molecular weight and temperature coefficient of ultrasonic velocity and boiling temperature has been derived following the theoretical treatment given by Kishimoto and Nomoto. This theoretical relation has been tested from the available data in organic liquids, liquified gases and molten metals and also the data obtained by the authors. It has been shown that Lagemann’s empirical relation is an approximation of this new relation. The deviations in some cases like alcohols, molten metals and liquified gases is attributed to molecular association in liquids and it is shown that better agreement will be obtained after applying a correction by using the association factor determined by Ramsay and Shield’s equation. A new relation between ultrasonic velocity and latent heat of vaporisation has also been obtained and confirmed by the experimental data for organic liquids, liquified gases and molten metals. This relation has also been obtained theoretically from thermodynamics.
