Equation Shchukarev

An equation of this type was first proposed by A. Shchukarev in 1896.294 A year later, A.A. Noyes and W.R. Whitney derived a similar equation.295 Its validity was then verified experimentally by L. Bruner and St. Tolloczko296 and E. Brunner 297... 

WOCl (g) obtained from the 2nd law analysis of the vapor pressure equation given by Shchukarev and Suvorov (4). See WOCl (g) table (Mar. 31, 1967) for details. 

Interestingly, Shchukarev equation, which included the separation surface area and equated the concentration on the inner side of the diffusion layer to the solubility value, was published in April 1896. But it was not noticed abroad where the priority was ascribed to A. Noyes and W. Witney who published their equation without considering the area only by the end of 1897. In 1900 their error was corrected, and in 1904 Nernst expanded the upgraded equation on all heterogeneous processes. For this reason this model mass transfer subsequently was treated as Nernst-Noyes equation. 

The rate of the mass transfer through the Nernst layer is defined by the rate of diffuse flow of reagents and products participating in chemical reactions on the interface. This rate was already reviewed as the adsorption rate in the process of film diffusion. It is based on the same Shchukarev equation (2.204). However, contrary to adsorption, here in the flow participate all ions formed in the process of dissolution, not just one ion. That is why in the equation (2.204) should be reviewed the flow of the mineral itself in solution, not of its individual ions, and its subscripts i should be replaced with ... 

Figure 2.37 Distribution of mineral j within the Nemst layer at dissolution under Shchukarev equation (A), under diffusive condition (B), under diffiise-kinetic condition (C) and under kinetic condition (D). C...

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