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Diffusivity of gases in liquids
J H Hildebrand1, R H Lamoreaux
1College of Chemistry, University of California, Berkeley, Calif. 94720.
Summary
Diffusion coefficients for various gases in carbon tetrachloride (CCl4) show a linear temperature dependence, converging to zero at the fluid
Area of Science:
- Physical Chemistry
- Chemical Engineering
Background:
- Understanding gas diffusion in liquids is crucial for chemical processes.
- Carbon tetrachloride (CCl4) and perfluorotributylamine ((C4F9)2N) represent distinct solvent environments.
Purpose of the Study:
- To investigate the diffusion coefficients of various gases in CCl4 and (C4F9)2N.
- To analyze the relationship between diffusion, temperature, and molecular properties.
Main Methods:
- Experimental determination of diffusion coefficients at atmospheric pressure.
- Analysis of diffusion behavior as a function of temperature and molecular characteristics.
Main Results:
- Diffusion coefficients in CCl4 exhibit a linear temperature dependence, converging to zero at the fluid's cessation point.
- Diffusion rates correlate inversely with molecular cross-section and directly with entropy of expansion.
- Diffusivities in (C4F9)2N do not converge with decreasing temperature, allowing diffusion even at low fluidity.
Conclusions:
- Gas diffusion in CCl4 is governed by temperature and molecular properties.
- The large, branched structure of (C4F9)2N alters diffusion behavior compared to smaller solvent molecules.
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