ABSTRACT
In the previous chapter various physicochemical measurements were described based on a diffusion column empty of any solid or liquid, and containing only interdiffusing gases. The diffusion current, of the solute into the carrier gas stream passing through the sampling column (cf. Fig. 3.1) was shown to be dependent only on the value of the mutual diffusion coefficient of the two gases. Suppose now that the diffusion column contains a solid or a liquid filling part or the entire length, L, of this column, and that the solute gas interacts in anyway with the solid or the liquid. This interaction could be physical (e.g., absorption of the gas by the liquid, adsorption of the gas on the solid, or diffusion into the pores of a porous material); or chemical (e.g., reaction of the solute gas with the solid, or with the liquid, or with substances adsorbed on the solid or dissolved in the liquid).
