Solubility polytherm and the influence of temperature on the enthalpy and entropy of dissolution

The significance and metrological meaning of parameters accessible to regressive estimates from the experimental data on solubility polytherms are refined using corollaries to the universal interrelation between the Gibbs energy, enthalpy, and entropy of dissolution. A standard procedure for processing solubility polytherms is suggested. Its informativeness is illustrated for the example of new metrologically verified data on the polytherm of solubility of ferrocene in pure water.     

On composite bands in the electronic absorption spectra of coordination compounds in solutions

Appearance of composite bands in resolved electronic absorption spectra was analyzed. Criteria for diagnostics of such bands, as well as a technique for their possible resolution into individual bands, were formalized and described.     

Saturated vapor pressure of individual substance. Supplement to interpretations and procedures for processing experimental polythermal data

A universal (that is, actual for any reaction) interconnection between enthalpy (∆_r H), entropy (∆_r S), and Gibbs energy (∆_r G) was applied to the analysis of the formation of saturated vapor of individual condensed (liquid and solid) substances. This allowed us to specify the conceptual and metrological sense of thermodynamic parameters available for estimation within the framework of tensimetric investigations. Proposals for the procedures of experimental data processing were made. The informativity of the approach was illustrated by the example showing the results of processing two arrays of primary data obtained using the static and the flow methods for crystal hafnium(IV) dipivaloylmethanate.     

The use of the terms formal element,initial and detailed components,and phase and chemical form in modeling of the states of homo- and heterogeneous systems

The terms formal element, initial and detailed components, and phase and chemical form and their use in chemical thermodynamic modeling of the state of substances in homo- and heterogeneous systems with taking into account local and partial equilibria are considered. The detailed component concept is introduced into fundamental equations. The use of the concept of formal elements is illustrated.     

Secondary environment effects on the first step of the protonation of SO 4 2− in saline aqueous solutions

The solubility of strontium sulfate in the mixtures of isomolar LiClO₄(NaClO₄) and HClO₄ aqueous solutions was determined at 25°C and ionic strengths of I = 0.5, 1.0, 2.0, 3.0, and 4.0. At I>-2, the solubility of SrSO₄ as a function of the hydrogen ion (HClO₄) concentration passes through a maximum, clearly showing a substantial contribution from environment effects (H⁺ substitution for Li⁺ or Na⁺), which counteract complexation (i.e., HSO ₄ ^? formation). A correct method for separating these two effects was proposed, and the parameters of the environment effect and the standard values of pSP° and logβ° were evaluated.     

Equilibria in ion exchanger-aqueous salt solution systems and clathrate formation

Russian Journal of General Chemistry - The new approach has been developed for the analysis of the data on the equilibria in the systems ionite-aqueous salt solution, based on the application of...     

Thermodynamic characteristics of the formation of silver(I) complexes with crown ether in an aqueous solution

Thermodynamic characteristics of complex formation of silver (I) with crown ether 18C6 are determined by polythermal potentiometry in the temperature range of 15?C35°C. The applicability of the regression analysis of experimental data is demonstrated, with allowance for the mutual compensation of the temperature effect on the enthalpy and entropy contributions to the Gibbs energy of complexation.