|
Journal of Physical Studies 19(3), Article 3603 [9 pages] (2015)
DOI: https://doi.org/10.30970/jps.19.3603 MUTUAL DIFFUSION IN THE LIQUID SOLUTION OF ACETONE-CYCLOHEXANE WITH A COMPLEX FORMATIONA. M. Kutsyk, V. V. Obukhovsky
Taras Shevchenko National University of Kyiv |
 |
A novel theoretical method is applied for the mutual diffusion description in binary liquid solutions. The non-linearity of the diffusion process is connected with the formation of molecular complexes during the dissolution process. This theory is applied for the analysis of mass transfer in the acetone-cyclohexane liquid solution. The concentration dependence of mutual diffusion in the investigated solution is highly non-linear. The minimal and maximal values of diffusion coefficients differ in almost three times. It is shown that the experimentally registered non-linearity of the mutual diffusion as a function of concentration can be explained if complex formation of the $[A_2C_1]$ type is taken into account ($A$ -- acetone, $C$ -- cyclohexane). Additionally, the usage of this theory allows to find the molecular complexes $[A_2C_1]$ concentration as a function of the initial composition characteristics. For the acetone-cyclohexane liquid solution the maximum of complex concentration was determined (it comes to 43\l.). A brief review of the most used approaches for the description of the mutual diffusion in liquid solutions was made. The accuracies of the theoretical description of mutual diffusion coefficient in the acetone-cyclohexane liquid solution were found by different methods. Their comparison was also carried out. It was shown that the nonlinear modification of the Fick law provides a satisfactory description of the experimental data. The increasing of accuracy of the mutual diffusion description can be reached by taking into account the formation of two types (or more) of molecular complexes.
PACS number(s): 66.10.-x