Showing papers on "Mass action law published in 2019"
TL;DR: In this article, the effect of diluents and tertiary amine on the liquid-liquid equilibrium was shown and quantified in terms of the predicted values of the distribution coefficient, chemical equilibrium constants, and temperature.
Abstract: The liquid–liquid equilibria of systems that involves lactic acid in the aqueous phase and tri-iso-octylamine with diluents as dodecane and 1-dodecanol (active or/and inert) were measured experimentally at three temperatures (306.15, 310.15, and 316.15 K). A previous liquid–liquid equilibrium model that is based on Nernst’s distribution law and mass action law equilibrium equations was extended and generalized for stoichiometric ratios (amine/acid) 1:n. The effect of the diluents and the tertiary amine on the liquid–liquid equilibrium is shown and quantified in terms of the predicted values of the distribution coefficient, chemical equilibrium constants, and temperature. The lactic acid concentration in equilibrium for the organic phase decreases as follows: water/LA/TiOA/1-dodecanol system > water/LA/TiOA/dodecane/1-dodecanol > system water/LA/TiOA/dodecane system.
4 citations
TL;DR: In this article, the effects of volume change at dissociation equilibrium of possible anion complexes of the (MX6)3− type in halide melts of trivalent metals MX3 within the statistical thermodynamics based on the MSA approximation were analyzed.
Abstract: The effects of volume change at dissociation equilibrium of possible anion complexes of the (MX6)3− type in halide melts of trivalent metals MX3 within the statistical thermodynamics based on the MSA approximation were analysed With the help of a simplified Akdeniz–Tosi model of a mixture of charged hard spheres of different diameters and valencies, we obtained the full system of equilibrium equations including the mass action law (MAL) and the equation of state (EoS) It was shown that the simplest approximation of the complex diameter as a tripled diameter of simple ions leads to a significant overestimation of the effects of volume changes at dissociation It was found that the complex dissociation should be accompanied by a significant increase in density in a narrow temperature interval It can be associated with the specific manifestation of electrolytic dissociation in the case of the trivalent metal halides’ auto-complexation
3 citations
03 Jul 2019
TL;DR: In this article, a new thermodynamic model, based on linearization of mass action law, modified for the ion exchange equation, is presented, which allows to define stoichiometry of ion exchange and the shape of ions adsorbed by the solid phase of ion-exchange resins, as well as to estimate equilibrium constant and Gibbs free energy of the process.
Abstract: A complex heterogeneous process of ion exchange can be defined with an isotherm-isobar equation of the chemical reaction, which describes differential affinity between the process and its effect – the law of mass action. Ion exchange includes processes accompanied by changes in the charge of ions and functional groups caused by the passing of ionic bond into covalent one. Hence isotherm equations of ion exchange for such processes must differ from conventional stoichiometric equations, but they can be obtained by classical study approaches to ion exchange equilibrium. The paper describes a new thermodynamic model, based on linearization of mass action law, modified for the ion exchange equation. The application of this model allows to define stoichiometry of ion exchange and the shape of ions adsorbed by the solid phase of ion-exchange resins, as well as to estimate equilibrium constant and Gibbs free energy of the process. Comparative analysis has been carried out for the thermodynamic model of cerium sorption in the form of anionic complex with Trilon B from a multisalt solution with ionic strength of 1 mol/kg (NaNO 3 ) under рН = 3 and temperature 298 K on a test sample of weak-base anion-exchange resin Cybber EV009. Experimental isotherm of the sorption has been obtained. Calculations of thermodynamic parameters have been performed using Langmuir, Freundlich, Dubinin – Radushkevich, Temkin and Flory – Huggins models, as well as thermodynamic model of linearized mass action law, proposed by the authors. Calculated values of the equilibrium constant and Gibbs energy – K = 9.0±0.5 and ΔrG 0 298 = –5.54±0.27 kJ/mol – characterize the sorption of EDTA cerate ions by ion-exchange resin. The shape of adsorbed ions has been defined in Stern-Helmholtz layer of CeTr, and total capacity of anion resin EV009 for EDTA cerate ions has been estimated as q ∞ = 2.0±0.1 mol/kg.
2 citations