The viscosity of pure substances in the dense gaseous and liquid phases

Abstract Viscosities available in the literature for the gaseous and liquid states of eleven substances have been correlated with reduced density by the use of dimensional analysis and the Abas‐zade expression for the residual viscosity to produce a single generalized relationship which is presented both graphically and analytically. The substances are argon, nitrogen, oxygen, carbon dioxide, sulfur dioxide, methane, ethane, propane, i ‐butane, n ‐butane, and n ‐pentane. The properties required for the calculation of viscosity with this relationship are the molecular weight, the critical constants, and the density of the substance at the temperature and pressure considered. Separate relationships were developed for hydrogen, ammonia, and water which do not follow the consistent behaviour of the other substances. Viscosity values for ethylene calculated with the generalized relationship compared favorably with the corresponding experimental values.