Diffusion of Kr in Kr-CH4 mixture

Experimental measurements of self-diffusion of Kr in Kr-CH4 mixture, at very low Kr concentration and at constant temperature of 203 K, are reported as a function of density in the density range 0<ϱ/ϱc<2. The experimental data are discussed together with those of self- diffusion of Kr and CH4, at nearly the same reduced temperature. Some conclusions have been reached about the mass dependence of the diffusion coefficient, and the first order coefficient of the density expansion.