Thermodynamic Study of the CuCl2-MCl2-H2O Systems (M = Mg, Co) at 298.15 K

1996 ◽  
Vol 61 (4) ◽  
pp. 507-511 ◽  
Author(s):  
Christomir Christov
Keyword(s):  
Thermodynamic Functions ◽  
Interaction Model ◽  
Thermodynamic Study ◽  
Interaction Parameters ◽  
Solubility Diagrams ◽  
Solubility Products ◽  
Ion Interaction Model ◽  
Good Agreement

The Pitzer ion-interaction model was used for a simulation of the CuCl2-MCl2-H2O (M = Mg, Co) systems at 298.15 K. The necessary thermodynamic functions (binary and ternary ion-interaction parameters and thermodynamic solubility products) were calculated and the theoretical solubility diagrams plotted. A very good agreement was obtained between the calculated and observed data.

Pitzer Model Based Study of CsX-NiX2-H2O (X = Cl, Br) Systems at 298.15 K

1996 ◽  
Vol 61 (4) ◽  
pp. 501-506 ◽  
Author(s):  
Christomir Christov
Keyword(s):  
Thermodynamic Functions ◽  
Interaction Model ◽  
Pitzer Model ◽  
Solubility Diagrams ◽  
Model Based ◽  
Solubility Products ◽  
Ternary Parameters ◽  
Ion Interaction Model ◽  
Good Agreement

The Pitzer ion-interaction model was used for simulating the CsX-NiX2-H2O (X = Cl, Br) systems at 298.15 K. The necessary thermodynamic functions (binary and ternary parameters, thermodynamic solubility products) were calculated and the theoretical solubility diagrams plotted. A very good agreement was found between the calculated and observed data.

Thermodynamic Study of Na2Cr2O7(aq) at 25 °C

1999 ◽  
Vol 64 (4) ◽  
pp. 595-599 ◽  
Author(s):  
Christomir Christov ◽  
Snejana Velikova ◽  
Kalina Ivanova ◽  
Stefan Tanev
Keyword(s):  
Thermodynamic Analysis ◽  
Binary Solution ◽  
Osmotic Coefficients ◽  
Interaction Model ◽  
Thermodynamic Characteristics ◽  
Thermodynamic Study ◽  
Isopiestic Method ◽  
Interionic Interaction ◽  
Ion Interaction Model

The isopiestic method was used to determine osmotic coefficients of binary Na2Cr2O7(aq) solutions of concentrations 0.6777-3.8792 mol kg-1 at 25 °C. The concentration of a saturated binary solution Na2Cr2O7(aq) at 25 °C was determined. The Pitzer ion-interaction model has been used for thermodynamic analysis of the results obtained. Optimum values of the binary parameters of interionic interaction have been calculated and important thermodynamic characteristics of Na2Cr2O7·2 H2O determined.

scholarly journals Mass-based hygroscopicity parameter interaction model and measurement of atmospheric aerosol water uptake

2011 ◽  
Vol 11 (11) ◽  
pp. 30877-30918
Author(s):  
E. Mikhailov ◽  
V. Merkulov ◽  
S. Vlasenko ◽  
D. Rose ◽  
U. Pöschl
Keyword(s):  
Water Vapor ◽  
Sodium Chloride ◽  
Relative Humidity ◽  
Aqueous Phase ◽  
Water Uptake ◽  
Atmospheric Aerosol ◽  
Interaction Model ◽  
Interaction Parameters ◽  
Vapor Supersaturation ◽  
Good Agreement

Abstract. In this study we derive and apply a mass-based hygroscopicity parameter interaction model for efficient description of concentration-dependent water uptake by atmospheric aerosol particles. The model approach builds on the single hygroscopicity parameter model of Petters and Kreidenweis (2007). We introduce an observable mass-based hygroscopicity parameter κm, which can be deconvoluted into a dilute intrinsic hygroscopicity parameter (κm,∞) and additional self- and cross-interaction parameters describing non-ideal solution behavior and concentration dependencies of single- and multi-component systems. For sodium chloride, the κm-interaction model (KIM) captures the observed concentration and humidity dependence of the hygroscopicity parameter and is in good agreement with an accurate reference model based on the Pitzer ion-interaction approach (Aerosol Inorganic Model, AIM). For atmospheric aerosol samples collected from boreal rural air and from pristine tropical rainforest air (secondary organic aerosol) we present first mass-based measurements of water uptake over a wide range of relative humidity (1–99%) obtained with a new filter-based differential hygroscopicity analyzer (FDHA) technique. By application of KIM to the measurement data we can distinguish three different regimes of hygroscopicity in the investigated aerosol samples: (I) A quasi-eutonic regime at low relative humidity (~60% RH) where the solutes co-exist in an aqueous and non-aqueous phase; (II) a gradually deliquescent regime at intermediate humidity (~60%–90% RH) where different solutes undergo gradual dissolution in the aqueous phase; and (III) a dilute regime at high humidity (≳90% RH) where the solutes are fully dissolved approaching their dilute intrinsic hygroscopicity. The characteristic features of the three hygroscopicity regimes are similar for both samples, while the RH threshold values vary as expected for samples of different chemical composition. In each regime, the concentration dependence of κm can be described by a simple KIM model equation based on observable mass growth factors and six fit parameters summarizing the combined effects of the dilute intrinsic hygroscopicity and interaction parameters of all involved chemical components. One of the fit parameters represents κm,∞ and can be used to predict CCN activation diameters as a function of water vapor supersaturation. For sodium chloride reference particles as well as for pristine rainforest aerosols consisting mostly of secondary organic matter, we obtained good agreement between the predicted and measured critical diameters of CCN activation. The application of KIM and mass-based measurement techniques shall help to bridge gaps in the current understanding of water uptake by atmospheric aerosols: (1) the gap between hygroscopicity parameters determined by HTDMA (hygroscopicity tandem differential mobility analyzer) or FDHA measurements under sub-saturated conditions and by CCN measurements at water vapor supersaturation, and (2) the gap between the results of simplified single parameter models widely used in atmospheric or climate science and the results of complex multi-parameter ion- and molecule-interaction models frequently used in physical chemistry and thermodynamics (AIM, E-AIM, UNIFAC, AIOMFAC etc.).

Study of the Conversion of CaSO4 to CaCO3 within the CaSO4 + Na2CO3 = CaCO3 + Na2SO4 Four-Component Water-Salt System

1995 ◽  
Vol 60 (12) ◽  
pp. 2107-2111 ◽  
Author(s):  
Dimitar Trendafelov ◽  
Christomir Christov ◽  
Christo Balarew ◽  
Aneta Karapetkova
Keyword(s):  
Free Energy ◽  
Calcium Sulfate ◽  
Interaction Model ◽  
Sea Salt ◽  
Salt System ◽  
Molar Gibbs Free Energy ◽  
High Dispersity ◽  
Water Salt ◽  
Solubility Products ◽  
Ion Interaction Model

The Pitzer ion-interaction model was employed to predict the conversion in the title quaternary water-salt system. The thermodynamic solubility products (Ks0) were determined and the conversion of CaSO4 to CaCO3 in the CaSO4 + Na2CO3 = CaCO3 + Na2SO4 system was predicted. The standard molar Gibbs free energy ∆rG0 of the conversion reaction was calculated to be -23.62 kJ mol-1. A 98% degree of conversion of CaSO4 was achieved by using calcium sulfate isolated from sea salt production waste brines. Suitable conditions were found for obtaining CaCO3 exhibiting a high dispersity and whiteness.

Simulation and Prediction of Solubility for the Quaternary System Containing Lithium, Sodium, Magnesium and Chloride at 273.15 K

2016 ◽  
Vol 873 ◽  
pp. 63-67
Author(s):  
Xing Yu Jiang ◽  
Lin Wang ◽  
Dong Chan Li
Keyword(s):  
Phase Diagram ◽  
Theoretical Basis ◽  
Quaternary System ◽  
Salt Lake ◽  
Interaction Model ◽  
Interaction Parameters ◽  
Solubility Predictions ◽  
Sodium Magnesium ◽  
Ion Interaction Model ◽  
Salt Lake Brine

Solubilities of the quaternary system containing lithium, sodium, magnesium and chloride at 273.15 K were calculated using Pitzer ion-interaction model and its extended HW model. The values of the Pitzer single-salt parameters β(0), β(1), β(2) and Cφ for LiCl, NaCl, and MgCl2, the mixed ion-interaction parameters θLi,Mg, θLi,Na, θNa,Mg, ψLi,Mg,Cl, ψLi,Na,Cl and ψNa,Mg,Cl, and the Debye–Hückel parameter Aφ in the quaternary system at 273.15K were derived. Based on the Jänecke indexes, the phase diagram was plotted. This study affords the necessary parameters for solubility predictions of complicated systems and establishes a theoretical basis for the separation of these valuable minerals from salt lake brine.

A New Look at Measurements of Network Density

1986 ◽  
Vol 59 (1) ◽  
pp. 138-141 ◽  
Author(s):  
Robert A. Hayes
Keyword(s):  
Hysteresis Loop ◽  
Interaction Parameters ◽  
Network Density ◽  
Stress Strain ◽  
Solvent Interaction ◽  
Solvent Method ◽  
Strain Data ◽  
Good Agreement ◽  
Polymer Solvent ◽  
New Look

Abstract A two-solvent method for determining the polymer-solvent interaction parameters independently of stress-strain data is described. The values obtained are much lower than those reported previously. Network densities calculated from swelling data and these interaction parameters are in good agreement with those calculated from the return portion of a hysteresis loop at high elongations.

Solubility Prediction for the Reciprocal Quaternary System (Li+, Mg2+//Cl-, SO42-–H2O) at 273.15 K Using Pitzer Ion-Interaction Model

2012 ◽  
Vol 549 ◽  
pp. 437-440 ◽  
Author(s):  
Shi Qiang Wang ◽  
Ya Fei Guo ◽  
Tian Long Deng
Keyword(s):  
Quaternary System ◽  
Salt Lake ◽  
Interaction Model ◽  
Linear Regression Method ◽  
Solubility Prediction ◽  
Temperature Dependent ◽  
Solubility Predictions ◽  
Multiple Linear Regression Method ◽  
Ion Interaction Model ◽  
Salt Lake Brine

Solubilities of the reciprocal quaternary system (Li+, Mg2+//Cl-, SO42-–H2O) at 273.15K were calculated using Pitzer and its extended HW model. The values of the Pitzer single-salt parameters β(0), β(1), β(2)and Cφfor LiCl, MgCl2, Li2SO4, and MgSO4, the mixed ion-interaction parameters θLi,Mg, θCl,SO4, ψLi,Mg,Cl, ψLi,Mg,SO4, ψLi,Cl,SO4and ψMg,Cl,SO4, and the Debye–Hückel parameter Aφin the system at 273.15K were derived either temperature-dependent equation or through fitting solubility data of the ternary system by multiple linear regression method. Based on the Jänecke indexes, the phase diagram was plotted. This study affords the necessary parameters for solubility predictions of complicated systems and establishes a theoretical basis for the separation of these valuable minerals from salt lake brine.

scholarly journals The Physical and Thermodynamic Functions of Borides

2017 ◽  
Vol 18 (1) ◽  
pp. 58-63
Author(s):  
N.Yu. Filonenko
Keyword(s):  
Free Energy ◽  
Physical Properties ◽  
Thermodynamic Functions ◽  
Point Of View ◽  
Energy Potential ◽  
High Temperature Expansion ◽  
Temperature Dependences ◽  
Function Calculation ◽  
First Time ◽  
Good Agreement

In the paper the physical properties and thermodynamic functions of borides Х2В (Х=W, Mo, Mn, Fe, Co, Ni та Cr) are studied with accounting for fluctuation processes. We use the microstructure analysis, the X-ray structural and the durometric analyses to determine the physical properties of alloys. In the paper it is determined the phase composition and physical properties of borides. In this paper for the first time it is determined the thermodynamic functions of borides using the Hillert and Staffansson model with accounting for the first degree approximation of high-temperature expansion for the free energy potential of binary alloys. We obtain the temperature dependences for such thermodynamic functions as Gibbs free energy, entropy, enthalpy and heat capacity Ср along with their values at the formation temperature for Х2В (Х=W, Mo, Mn, Fe, Co, Ni та Cr). The approach under consideration enables to give more thorough from the thermodynamic point of view description of borides formed from the liquid. The outcomes of the thermodynamic function calculation for borides are in good agreement with experimental data and results of other authors.

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