Review of relation between diffusivity and solvent viscosity in dilute liquid solutions

✍ Scribed by W. Hayduk; S.C. Cheng

• Publisher: Elsevier Science
• Year: 1971
• Tongue: English
• Weight: 1012 KB
• Volume: 26
• Category: Article
• ISSN: 0009-2509
• DOI: 10.1016/0009-2509(71)86007-4

✦ Synopsis

Diffusivities measured at 25°C are reported for ethane in normal hexane, heptane, octane, dodecane and hexadecane, and at 25°C and 50°C for carbon dioxide in hexadecane. Measurements were made by means of the steady-state capillary cell technique. The general relation between diffusivities in dilute liquid solutions and solvent viscosities for non-complexing systems was reviewed. It was found that in general diffusivity and solvent viscosity were not inversely related but that the diffusivity depended on the solvent viscosity raised to some power which was variable, depending on the diffusing substance. Niether the temperature, nor solvent molecular weight or molar volume was required to describe the observed relationship between the ditfusivities and solvent viscosities for eleven different substances, for a range of temperatures, solvents, and binary solvent compositions. The observed relationship would appear to provide an improved basis for correlating liquid diffusivities in dilute liquid solutions.