Some phase relationships between basic bismuth chlorides in aqueous solutions at 25 °C

1987 ◽  
Vol 65 (12) ◽  
pp. 2824-2829 ◽  
Author(s):  
Peter Taylor ◽  
Vincent J. Lopata
Keyword(s):  
Aqueous Solutions ◽  
Equilibrium Constants ◽  
Natural Occurrence ◽  
Chloride Solutions ◽  
Gibbs Energies ◽  
Activity Ratios ◽  
Aqueous Chloride ◽  
The Stability ◽  
Experimental Values ◽  
Phase Relationships

Observations are reported on the interconversion of solid α-Bi2O3, Bi12O17Cl2, BiOCl, and a daubréeite-like phase tentatively identified as Bi2O2(OH)Cl, in aqueous chloride solutions at 25 °C. Equilibrium constants, K, for these interconversions are expressed as anion activity ratios, {Cl−}/{OH−}. Experimental values of K for equilibrium between Bi2O3 and each of the chlorides are 100.56 ± 0.20 for Bi12O17Cl2, 101.5 ± 0.4 for Bi2O2(OH)Cl, and 103.13 ± 0.04 for BiOCl; the fatter two represent metastable equilibria. These equilibrium constants yielded the following estimates of Gibbs energies of formation: Bi12O17Cl2, −3141 ± 6 kJ mol−1;"Bi2O2(OH)Cl", −696 ± 4 kJ mol−1; BiOCl, −321.5 ± 1.3 kJ mol−1. Phase relationships among these solids are discussed, with reference to natural occurrence, other bismuth oxychlorides, and the stability of other basic salts of bismuth.

Evaluation of thermodynamic properties and correlation of L-glutamic acid solubility in some aqueous chloride solutions from 298.15 to 323.15 K

2019 ◽  
Vol 97 (8) ◽  
pp. 615-620
Author(s):  
Mustafa Jaipallah Abualreish ◽  
Adel Noubigh
Keyword(s):  
Thermodynamic Properties ◽  
Aqueous Solutions ◽  
Glutamic Acid ◽  
Pure Water ◽  
Gravimetric Method ◽  
Chloride Salt ◽  
Salting Out ◽  
Chloride Solutions ◽  
Aqueous Chloride ◽  
The Impact

This paper investigates the solubility–temperature dependence data for L-glutamic acid (Glu) in water and in some chloride salt (NaCl and KCl) aqueous solutions. Solubility data were determined from 293.15 to 318.15 K under atmospheric pressure by using a thermostatted reactor and the gravimetric method. After the investigation of the impact of inorganic salts on the solvency of Glu, it was found that the salting-out effect decreases in the following order: sodium chloride > potassium chloride. Results demonstrated that the solubility, in unadulterated water and in aqueous chloride solutions, increased with a rising temperature. The experimental data were well correlated by the semi-empirical equation. Using the measured solubilities, the standard molar thermodynamic properties of transfer of Glu (ΔtrG°, ΔtrH°, and ΔtrS°) from pure water to aqueous solutions of the chloride salts were estimated.

A SPECTROPHOTOMETRIC REEXAMINATION OF THE SPECTRA AND STABILITIES OF THE IRON (III) – TIRON COMPLEXES

1964 ◽  
Vol 42 (8) ◽  
pp. 1917-1927 ◽  
Author(s):  
W. A. E. McBryde
Keyword(s):  
Aqueous Solutions ◽  
Stability Constants ◽  
Equilibrium Constants ◽  
Sodium Perchlorate ◽  
Potassium Nitrate ◽  
Low Ph ◽  
Exact Nature ◽  
Simple Complex ◽  
Acidity Constants ◽  
The Stability

Variations in the spectra of the aqueous solutions of the iron (III) – sodium catechol disulphonate (Tiron) complexes may be interpreted in relation to pH of the solutions to show which complexes are present at any chosen pH. With this knowledge it is possible in this system to evaluate equilibrium constants for the formation of each complex in turn. Combining these with separately determined acidity constants for Tiron, the stability constants of the complexes may be calculated. These have been determined for background solutions of potassium nitrate or sodium perchlorate each at three different concentrations, and for three different ratios of reagent to metal. Averages of a number of determinations made under these conditions are given in Table III of the paper. The constant K1 in perchlorate media shows an unmistakable dependence suggestive of the existence of a protonated species at low pH as well as the simple complex ML. However, there is some ambiguity in the interpretation of the results so that the exact nature of the protonated complex cannot be decided.

Excess free energies of mixing of Sr,Ba-bearing binary feldspar solid solutions (experimental data)

1995 ◽  
Vol 59 (394) ◽  
pp. 79-91 ◽  
Author(s):  
A. R. Kotelnikov ◽  
I. V. Chernysheva
Keyword(s):  
Solid Solutions ◽  
Phase State ◽  
Excess Energy ◽  
Free Energies ◽  
Chloride Solutions ◽  
Energy Of Mixing ◽  
Aqueous Chloride ◽  
The Stability ◽  
The Relationship ◽  
Excess Energy Of Mixing

AbstractThe distribution of potassium and strontium, potassium and barium between feldspars and aqueous chloride solutions was studied at 700°C, 2 kbar and 800°C, 2 kbar respectively. The distribution of Sr and Ba between coexisting feldspar and chloride solutions is not ideal; Sr and Ba are enriched in feldspar relative to solution. In order to estimate the phase state of the chloride solutions, special experiments were conducted using the synthetic fluid-inclusion method in the systems KCl-BaCl2-H2O and KCl-SrCl2-H2O at 700–800°C, 2 kbar. It was shown that (0.5M KCl+0.5M SrCl2) aqueous solution is homogeneous at 800°C, 2 kbar. The 0.25–0.5M SrCl2 solutions are homogeneous at 700°C 2, kbar. The (0.5M KCl+0.5M BaCl2) solution is homogeneous at 700°C, 2 kbar and heterogeneous at 800°C, 2 kbar. Margules parameters for describing the excess energy of mixing of the (K,Sr)- and (K,Ba)-feldspar solid solutions were calculated. The integrated values of excess energy of mixing () were estimated for the different binary feldspar solid solutions, and a correlation of with the crystallochemical parameter ρ = (RA-RB)/D(Me-O) was observed. Feldspar solid solutions can be subdivided into three groups based on the relationship between , p and the stability of the solid solution.

Extraction of strontium and barium salts by the nitrobenzene solution of dicarbolide in the presence of glymes

1985 ◽  
Vol 50 (3) ◽  
pp. 581-599 ◽  
Author(s):  
Petr Vaňura ◽  
Emanuel Makrlík
Keyword(s):  
Stability Constants ◽  
Organic Phase ◽  
Equilibrium Constants ◽  
Minor Role ◽  
Nitrobenzene Solution ◽  
Ligand Structure ◽  
Stability Constants Of Complexes ◽  
Separation Factors ◽  
The Stability ◽  
A Minor

Extraction of microamounts of Sr2+ and Ba2+ (henceforth M2+) from the aqueous solutions of perchloric acid (0.0125-1.02 mol/l) by means of the nitrobenzene solutions of dicarbolide (0.004-0.05 mol/l of H+{Co(C2B9H11)2}-) was studied in the presence of monoglyme (only Ba2+), diglyme, triglyme, and tetraglyme (CH3O-(CH2-CH2O)nCH3, where n = 1, 2, 3, 4). The distribution of glyme betweeen the aqueous and organic phases, the extraction of the protonized glyme molecule HL+ together with the extraction of M2+ ion and of the glyme complex with the M2+ ion, i.e., ML2+ (where L is the molecule of glyme), were found to be the dominating reactions in the systems under study. In the systems with tri- and tetraglymes the extraction of H+ and M2+ ions solvated with two glyme molecules, i.e., the formation of HL2+ and ML22+ species, can probably play a minor role. The values of the respective equilibrium constants, of the stability constants of complexes formed in the organic phase, and the theoretical separation factors αBa/Sr were determined. The effect of the ligand structure on the values of extraction and stability constants in the organic phase is discussed.

The metachor as a characteristic of the association of electrolytes in aqueous solutions

1984 ◽  
Vol 49 (5) ◽  
pp. 1061-1078 ◽  
Author(s):  
Jiří Čeleda ◽  
Stanislav Škramovský
Keyword(s):  
Aqueous Solutions ◽  
Apparent Volume ◽  
Solutions Of Electrolytes ◽  
Molal Volumes ◽  
The Difference ◽  
High Concentrations ◽  
Experimental Values ◽  
Suitable Characteristic ◽  
Association Of Ions ◽  
Very High

Based on the earlier paper introducing a concept of the apparent parachor of a solute in the solution, we have eliminated in the present work algebraically the effect which is introduced into this quantity by the additivity of the apparent molal volumes. The difference remaining from the apparent parachor after substracting the contribution corresponding to the apparent volume ( for which the present authors suggest the name metachor) was evaluated from the experimental values of the surface tension of aqueous solutions for a set of 1,1-, 1,2- and 2,1-valent electrolytes. This difference showed to be independent of concentration up to the very high values of the order of units mol dm-3 but it was directly proportional to the number of the free charges (with a proportionality factor 5 ± 1 cm3 mol-1 identical for all studied electrolytes). The metachor can be, for this reason, a suitable characteristic for detection of the association of ions and formation of complexes in the solutions of electrolytes, up to high concentrations where other methods are failing.

The reactions of oligoalcohols with arsenic, arsenous, boric and germanic acids

1980 ◽  
Vol 45 (10) ◽  
pp. 2645-2655 ◽  
Author(s):  
Antonín Mikan ◽  
Miloš Bartušek
Keyword(s):  
Aqueous Solutions ◽  
Equilibrium Constants ◽  
Dilute Aqueous Solutions

The reactions of sorbitol, mannitol, adonitol, dulcitol, glucose and glycerol with H3AsO4, H3AsO3, H3BO3 and GeO2 acids in dilute aqueous solutions were studied by potentiometric neutralization titrations. The formation of the following chelates was demonstrated: As(V)L3-, As(III)L(OH)2-, HAs(III)L(OH)2, BL2-, GeL2(OH)- and GeL32- and the equilibrium constants for their formation were found. Conditions for formation of these chelates of organic oligohydroxy compounds are discussed.

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