Solubility in the systems KClO4-RbClO4-H2O,KBrO3-RbBrO3-H2O,KIO3-CsIO3-H2O,RbClO4-CsClO4-H2O,RbBrO3-CsBrO3-H2O,RbIO3-CsIO3-H2O at 25°

Conclusions The solubility in the systems KClO₄-RbClO₄-H₂O, KBrO₃-RbBrO₃-H₂O, KIO₃-CsIO₃-H₂O, RbClO₄-CsClO₄-H₂O, RbBrO₃-CsBrO₃-H₂O, RbIO₃-CsIO₃-H₂O was studied at 25°. In all cases the formation of continuous series of solid solutions was established.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 12, pp. 2631–2634, December, 1971.The authors would like to express their gratitude to A. I. Vulikh for his constant interest in this work and his valuable advice.     

Glass formation in the ZnCl2-H2O system

A scheme of structural groups responsible for glass formation in the ZnCl₂-H₂O system was proposed. Possible glass formation mechanisms in the ZnCl₂-H₂O system and in glassy ZnCl₂ were compared.     

DTA-TG Study of the CaO-SiO2-H2O and CaO-Al2O3-SiO2-H2O Systems Under Hydrothermal Conditions

Simultaneous DTA-TG is an excellent technique for evaluating phases formed in hydrothermally treated CaO-SiO₂-H₂O and CaO-Al₂O₃-SiO₂-H₂O systems. Thermal analysis in combination with XRD and SEM, revealed that in the CaO-Al₂O₃-SiO₂-H₂O system the amount of hydrogarnet formed was the largest when gibbsite was used as the Al source, smallest for kaolin and intermediate for metakaolin. The endotherm peak temperature of the hydrogarnet dehydration endotherm was affected by the amount of hydrogarnet and the Si content of hydrogarnet. The thermal stability and structural order of 11 Å tobermorite were reduced with the incorporation of Al and, as a result, 11 Å tobermorite transformed into 9.3 Å tobermorite at lower temperatures while the transformation of the latter into beta-wollastonite required more energy. There exists a direct relationship between the 9.3 Å tobermorite and beta-wollastonite formation temperatures. Solid-state ²⁹Si and ²⁷Al MAS NMR data support these findings.     

Investigation of peroxyhydrates and hydrates of rubidium and cesium carbonates Communication 2. Physicochemical study of the ternary system Rb2CO2-H2O2-H2O

Conclusions A physicochemical investigation of the system Rb₂CO₃-H₂O₂-H₂O in the region of high hydrogen peroxide concentrations at low temperatures revealed for the first time the formation of a peroxyhydrate with a high hydrogen peroxide content, of the composition Rb₂CO₃ · 6H₂O₂.     

Untersuchung der Cokristallisation in den Systemen. Mn(OOCCH3)2-Co(OOCCH3)2-H2O,Mn(OOCCH3)2-Ni(OOCCH3)2-H2O,Mn(OOCCH3)2-Zn(OOCCH3)2-H2O bei 60°C

Investigation of Cocrystallization in the Systems Mn(OOCCH₃)₂-Co(OOCCH₃)₂-H₂O, Mn(OOCCH₃)₂-Ni(OOCCH₃)₂-H₂O, Mn(OOCCH₃)₂-Zn(OOCCH₃)₂-H₂O at 60°C The three-component systems Mn(OOCCH₃)₂-Co(OOCCH₃)₂-H₂O, Mn(OOCCH₃)₂-Ni(OOCCH₃)₂-H₂O and Mn(OOCCH₃)₂-Zn(OOCCH₃)₂-H₂O at 60°C were investigated by physio-chemical analysis. There is an interruption in the series of mixed crystals formed in the three-component systems. The inclusion of Co²⁺- and Ni²⁺ in Mn(OOCCH₃)₂ · 2 H₂O of Mn²⁺ in Co(OOCCH₃)₂ · 2 H₂O, Zn(OOCCH₃)₂ · 2 H₂O and Ni(OOCCH₃)₂ · 4 H₂O is based on isodimorphic substitution. It was found that in the system Mn(OOCCH₃)₂-Zn(OOCCH₃)₂-H₂O crystallizes Zn(OOCCH₃)₂ · Mn(OOCCH₃)₂ · 2 H₂O. It was identified by the X-ray and differential thermal analysis.     

Thermodynamic analysis of metal dusting on iron in CO-H2-H2O atmosphere

This paper provides a calculation method for carbon activity in CO-H2-H2O atmosphere. The thermodynamic parameters (aC) gas (carbon activity in environment) of different compositions at any temperature can be obtained by △G^o T. A theoretical analysis has been conducted into the thermodynamic role of iron and the dependence of possible metal-dusting occurrence on temperature, gas composition and total pressure. In CO-H2-H2O gas mixtures, decreasing the molar fraction of H2O and increasing total pressure expands the temperature region for metal dusting. In CO-H2-H2O gas mixture of different compositions at any temperature and pressure for Fe, depending on relative values of (aC) gas , (aC) Fe3C/Fe and aC = 1, three zones were found to exist.     

Electrical conductivity of solutions of the LiIO3-HIO3-H2O system

The electrical conductivity of aqueous LiIO₃ solutions and solutions of the LiIO₃-HIO₃-H₂O system is measured over a wide range of compositions at 25, 50, and 75°C. Isothermal surfaces of electrical conductivity are mapped, and the activation energies of conductivity are calculated. The conductivity isotherms in the LiIO₃-H₂O and HIO₃-H₂O boundary binary systems and in mixed solutions along sections with fixed electrolyte ratios each have a maximum as a function of electrolyte concentration. It is assumed that structure reorganization occurs in solutions in the concentration range corresponding to the peak conductivity. Proton migration features in the solutions in question are considered.     

Das System Ca(N3)2-H2O

Zusammenfassung Das Zustandsdiagramm für das System Ca(N₃)₂-H₂O wird auf Grund von Gefrierpunkts- und Löslichkeitsmessungen auf-gestellt. Ferner werden Lösungswärmen bestimmt und Dampfdruckmessungen vorgenommen. Durch Aufstellen eines Kreisprozesses werden die Normalbildungsenthalpien folgender Verbindungen bestimmt: Ca(N₃)₂, Ca(N₃)₂·0,5 H₂O, Ca(N₃)₂·1,5 H₂O und Ca(N₃)₂·4 H₂O.

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The system Ca(N₃)₂-H₂O

Based on measurements of freezing points and solubility the phase diagram of the system Ca(N₃)₂-H₂O is given. Furthermore, investigations on the heat of solution and measurements of the vapor pressure were carried out. By setting up a cycle process the standard enthalpies of formation for the following compounds were determined: Ca(N₃)₂, Ca(N₃)₂·0,5 H₂O, Ca(N₃)₂·1,5 H₂O and Ca(N₃)₂·4 H₂O.

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Mit 2 Abbildungen     

Computer simulation of interactions in the NH3-CO2-H2O system

Computer simulation of interactions in the NH₃-CO₂-H₂O system was performed using a quantum-chemical method B3LYP/6-31G(d,p) for the simulation of the possible routes of the reactions and the estimation of the energy parameters: interaction energy between molecules in complexes, activation energy of forward and reverse reactions, and the heat of the reaction. A new version of termolecular reaction mechanism is proposed and investigated. The probability of realization of various paths of interaction in the NH₃-CO₂-H₂O system was shown to be determined by the temperature: at low temperatures the termolecular mechanism is more probable, while at the temperatures close to the standard conditions carbamate and bimolecular mechanisms are preferable.     

Reactions in the M(HCOO)2-CS(NH2)2-H2O (M = Mg, Mn, Cd) systems at 25°C

Complex formation in the M(HCOO)₂-CS(NH₂)₂-H₂O (M = Mg, Mn, Cd) systems at 25°C is studied using the isothermal solubility method. In the Cd(HCOO)₂-CS(NH₂)₂-H₂O system, a congruently dissolving compound Cd(HCOO)₂ · 2CS(NH₂)₂ is found and characterized by X-ray powder diffraction and IR spectroscopy. The Mg(HCOO)₂-CS(NH₂)₂-H₂O and Mn(HCOO)₂-CS(NH₂)₂-H₂O systems are eutonics at this temperature. Data on carbamide and thiocarbamide complexes of divalent metal formates are systematized.     

Properties of Systems Ba(HCOO)2-M(HCOO)2-H2O (M = Ca or Mg) at 25°C

The systems Ba(HCOO)₂-Ca(HCOO)₂-H₂O and Ba(HCOO)₂-Mg(HCOO)₂-H₂O were studied at 25°C by the solubility method. The effect of the ionic radii of doubly charged metals on the formation of double salts containing barium formate was considered.     

The physicochemical properties of the LiCl-CeCl3-H2O ternary system

The density, viscosity, refractive index, heat conductivity, heat capacity, and freezing temperature of the LiCl-CeCl₃-H₂O ternary system were experimentally determined over the lithium and cerium chloride concentration ranges 13–20 and 8–14 wt %, respectively, and the temperature range ?50–35°C. The densities and viscosities of the LiCl-CeCl₃-H₂O ternary system were calculated by various methods from the properties of binary solutions. The calculation results were compared with the experimental data. The possibilities and shortcomings of each of the methods used are discussed.     

Glass formation and gelation in the system K2O-SiO2-H2O

Systems produced in interaction of colloid SiO₂ particles with potassium hydroxide solutions form, as a result of aging, solid transparent gels and jellies. Depending on the pH value, the systems formed retain the colloid structure or take features of a homogeneous glassy body, with the glass formation possible within a rather large area in the K₂O-SiO₂-H₂O triangle, adjacent to the K₂O-SiO₂ line.     

Systems AIPUO6-H2O (AI = Na,K): Phase Diagrams and Thermochemistry

The ranges of existence of crystal hydrates in the systems NaPUO₆-H₂O and KPUO₆-H₂O were studied by isopiestic and static tensimetric methods. All the compounds formed in these systems were isolated and studied by reactive calorimetry. The enthalpies of their formation and dehydration were determined.     

Glass formation in the systems Al2(SO4)3-MSO4-H2O (M = Cd2+, Zn2+, Mg2+) and Al2(SO4)3-Fe2(SO4)3-H2O

The glass formation region boundaries were found in the systems Al₂(SO₄)₃-MSO₄-H₂O, where M = Cd²⁺, Zn²⁺, and Mg²⁺, and Al₂(SO₄)₃-Fe₂(SO₄)₃-H₂O. The causes of the differences in glass-forming ability between the studied systems were analyzed. The structures and properties of glassy Al₂(SO₄)₃ · 11H₂O and Fe₂(SO₄)₃ · 11H₂O were compared.     

Physicochemical investigation of the ternary system KF-H2O2-H2O

Conclusions An investigation of the fusibility in the system KF-H₂O₂-H₂O confirmed the existence of KF · H₂O₂ and demonstrated the formation of a new compound, KF · 2H₂O₂, which exists in the system in the interval from –70 to 20° in the region of high hydrogen peroxide concentrations.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 3, pp. 491–494, March, 1973.     

Phase Formation in the System FeOOH-Zn(OH)2-H2O under Hydrothermal Conditions

Sequence of chemical transformations occurring in the system FeOOH-Zn(OH)₂-H₂O in the course of heat treatment at 125-200°C was studied by X-ray phase analysis, electron microscopy, and chemical analysis.     

Phase formation in the HfO(NO3)2-H3PO4-CsF(HF)-H2O system

The phase formation in the system HfO(NO₃)₂-H₃PO₄-CsF(HF)-H₂O was studied along the sections at the molar ratios PO ₄ ^3? /Hf = 0.5, 1.5, and 2.0 and RbF:Hf = 1?C5, and also in the presence of HF at CsF: Hf = 1. The initial solutions contained 2?C24 wt % HfO₂. The synthesis was performed at room temperature. The following substances were isolated: crystalline cesium fluorophosphate hafnates CsHf₂F₆PO₄ · 4H₂O, CsHfF₂PO₄ · 0.5H₂O, and CsH₂Hf₂F₂(PO₄)₃ · 2H₂O; X-ray amorphous cesium fluorophosphate hafnate of the average composition Cs₂Hf₃O_1.5F₅(PO₄)₂ · 5H₂O; and X-ray amorphous cesium fluorophosphate nitrate hafnate Cs₅H₄Hf₃F₇(PO₄)_3.66(NO₃)₃ · 5H₂O. The compositions of the amorphous phases should be refined. Cesium fluorophosphate hafnates were obtained for the first time. The compounds were studied by crystal-optical, elemental, X-ray diffraction, IR spectroscopic, and electron microscopic analyses.     

Calculations of chemical equilibria in Tb(NO3)3-H2O, Tb(NO3)3-heparin-H2O, and CaCl2-Tb(NO3)3-heparin-H2O systems in physiological saline solution

Chemical equilibria in the heterogeneous system Tb(NO₃)₃-H₂O, physiological saline solutions containing terbium nitrate, and unfractionated heparin ((H₄L) Tb(NO₃)₃-H₄L-H₂O-NaCl), and solutions containing calcium chloride, terbium nitrate, and unfractionated heparin (CaCl₂-Tb(NO₃)₃-H₄L-H₂O-NaCl) were studied by mathematical modeling and pH titration. A physicochemical model was designed for two-phase equilibria in the system Tb(NO₃)₃-H₂O, which consists of an aqueous solution and a solid phase of precipitated terbium hydroxide. Formation constants were calculated for terbium hydroxide ions Tb(OH) _i ^(3?i)+ (i = 1, 2, 3) in an aqueous phase, and a correlation was found between the amount of precipitated Tb(OH) ₃ ⁱ and pH. The four-component solution Tb(NO₃)₃-H₄L-H₂O-NaCl in the range 2.3 ≤ pH ≤ 10.4 is homogeneous; as a result of its investigation, the formation constants were ascertained for significant terbium complexes with heparin: TbL, TbHL ₂ ⁴ , and Tb(OH)₂L^3?. Chemical equilibria in the five-component solution CaCl₂-Tb(NO₃)₃-H₄L-H₂O-NaCl were modeled proceeding from the models developed for equilibria in the four-component solution subsystems Tb(NO₃)₃-H₄L-H₂O-NaCl and CaCl₂-H₄L-H₂O-NaCl. The modeling showed that the Tb³⁺ ion is an efficient competitive complex former to the Ca²⁺ ion, which forms complexes with heparin, and decreases tenfold the concentration of the major complex NaCaL at 6.8 ≤ pH ≤ 7.4 (the pH range of blood plasma stability).     

ChemInform Abstract: Cross Sections and Product Kinetic Energy Analysis of H2O+-H2O Collisions at Suprathermal Energies.

The H₂O⁺-H₂O reaction is studied at center-of-mass collision energies in the range 0.5-25 eV.