METHOD OF DETERMINING COEFFICIENT OF MUTUAL DIFFUSION OF GAS MOLECULES Russian patent published in 2016 - IPC G01N13/00 

FIELD: molecular physics.

SUBSTANCE: invention can be used for measurement of coefficient of mutual diffusion of molecules of gases. Method consists in fact that a diffusion cell in form of a transparent capillary tube partially filled with liquid, one end of which is tightly closed, and other one remains open into external homogeneous gas medium (atmospheric air or special reference gas-standard specimen with values of composition). During evaporation near surface of liquid vapour is saturated and has maximum possible partial pressure and concentration of molecules. Molecules evaporated from liquid crosses distance from its surface to open into external gas medium end of capillary tube by diffusion. Free surface of liquid, observed in microscope, equipped with measuring and calibrating scales, due to evaporation of molecules is moved along capillary tube over time, moving away from free end. Square distance fluid surface from free end of capillary x² has linear dependence on time of observation t. Determination of graphics x²(t) angular coefficient k of this relationship, mutual diffusion coefficient D by formula:

EFFECT: technical result is simple and accurate method for determining coefficient of mutual diffusion of molecules of gaseous vapours of analysed liquid and external gas.

1 cl, 2 dwg