Thermochemistry of uranium compounds V. Standard enthalpies of formation of the monouranates of lithium,potassium, and rubidium

Enthalpies of reaction, ΔH_r, of the monouranates of lithium, potassium, and rubidium with 1 mol dm^?3 HCl have been measured calorimetrically. From these measurements, and auxiliary determinations of the enthalpies of solution in acid of the chlorides of lithium, potassium, and rubidium and of uranyl chloride, the standard enthalpies of formation of the uranates, ΔH_f^o, have been derived. The results obtained are as follows:

     

2.

Caesium nitrate (II) at 296 K     

D. Pohl  T. Gross 《Acta Crystallographica. Section C, Structural Chemistry》1993,49(2):316-318

     

3.

Reaction of ethynylsilanes with certain aliphatic polyhalides     

M. F. Shostakovskii  N. V. Komarov  O. G. Yarosh 《Russian Chemical Bulletin》1969,18(9):1913-1914

     

4.

Caesium salts of titanium,zirconium and thorium cyanoferrates(II)     

V. Kouřím  M. Lázníček  J. Doležal 《Journal of Radioanalytical and Nuclear Chemistry》1974,21(2):355-362

The synthesis of cyanoferrates of quadrivalent metals and the sorption of caesium ions by these materials have been studied. It has been found that the compositions of the compounds and their properties are strongly influenced by the degree of hydrolysis of the metal. These is no sorption of caesium by Zr⁴⁺ and Th⁴⁺ cyanoferrates, while the compounds of oxygencontaining bivalent complex cations exhibit behaviour similar to that of the other bivalent metals. The sorption of caesium by (TiO)₂R is govermed by an ion-exchange mechanism; with (ZrO)₂R changes occur in the crystal lattice, and (ThO)₂R exhibits a low affinity towards caesium.     

5.

Crystal structure of rubidium pentabromodistannate(II)     

《Polyhedron》1986,5(10):1593-1596

     

6.

Thermochemistry of decomposition of manganese(II) oxalate dihydrate     

Michael Ewart Brown  David Dollimore  Andrew K. Galwey 《Thermochimica Acta》1977,21(1):103-110

Differential scanning calorimetry (DSC) has been used to determine the enthalpy of dehydration of manganese(II) oxalate dihydrate and the enthalpies of decomposition in nitrogen and in oxygen of the anhydrous oxalate. The thermodynamic data have been related to the activation energies reported in kinetic studies and to the mechanisms proposed for the thermal decomposition and oxidation processes.     

7.

Reaction of organic compounds of pentavalent antimony with polyhalides     

A. N. Nesmeyanov  A. E. Borisov  N. G. Kizim 《Russian Chemical Bulletin》1974,23(7):1602-1602

     

8.

Electronically excited rubidium atom in helium clusters and films. II. Second excited state and absorption spectrum     

Leino M  Viel A  Zillich RE 《The Journal of chemical physics》2011,134(2):024316

Following our work on the study of helium droplets and film doped with one electronically excited rubidium atom Rb(?) ((2)P) [M. Leino, A. Viel, and R. E. Zillich, J. Chem. Phys. 129, 184308 (2008)], we focus in this paper on the second excited state. We present theoretical studies of such droplets and films using quantum Monte Carlo approaches. Diffusion and path integral Monte Carlo algorithms combined with a diatomics-in-molecule scheme to model the nonpair additive potential energy surface are used to investigate the energetics and the structure of Rb(?)He(n) clusters. Helium films as a model for the limit of large clusters are also considered. As in our work on the first electronic excited state, our present calculations find stable Rb(?)He(n) clusters. The structures obtained are however different with a He-Rb(?)-He exciplex core to which more helium atoms are weakly attached, preferentially on one end of the core exciplex. The electronic absorption spectrum is also presented for increasing cluster sizes as well as for the film.     

9.

Lithium and Caesium Hydrogen Glutarate     

A. L. Macdonald  A. Murray  A. A. Freer  K. Henderson 《Acta Crystallographica. Section C, Structural Chemistry》1995,51(3):404-406

     

10.

Thermochemistry of thermal plasma chemical reactions. Part II. A survey of synthesis routes for silicon nitride production     

Yl Chang  R. M. Young  E. Pfender 《Plasma Chemistry and Plasma Processing》1987,7(3):299-316

Feasibility routes for thermal plasma production of silicon nitride powders are explored. First, a collation of the various proposed systems from the extant literature is examined. Reactant systems investigated include free silicon, silicon monoxide, silicon dioxide, silicon tetrachloride, silane, and other organosilicon precursors, along with various nitriding and reducing species. The reaction yields of these systems are brought to a common denominator by thermodynamic analysis and a first-step introduction of nucleation kinetics including comparisons against published experiments and the authors' own research. In particular, it is observed that the formation of liquid-phase free silicon in the neighborhood of 2500 K is quite detrimental to silicon nitride yield, and furthermore, a high supersaturation of silicon should always be avoided.     

11.

Thermochemistry of Binding of Lead(II) and Cadmium(II) by Saccharides in Aqueous Solution     

Jennifer E. Mihalick  William P. Griffiths III  James E. Muten  Travis A. Olson  John B. Hein 《Journal of solution chemistry》1999,28(8):1019-1030

Solution calorimetry was used to determine enthalpies and stability constants for binding of lead(II) or cadmium(II) by galacturonic acid and several monosaccharides in aqueous solution. New values for enthalpies of solution in water are reported for galacturonic acid and maltose monohydrate. The interaction of water solvent with the reactants is the largest factor in the binding process.     

12.

Thermochemistry of nonaqueous solutions of electrolytes: II. Heat of solution of sodium iodide in water-dioxane     

Mishchenko  K. P.  Shadskii  S. V. 《Theoretical and Experimental Chemistry》1965,1(1):36-39

The heats of solution of sodium iodide in water and water-dioxane (45. 95, 52. 55, and 68. 15% by wt dioxane at 25° (also for 2° for the first of these mixtures) are reported. The process becomes more exothermic as the dioxane content increases; a qualitative interpretation. The temperature coefficient of the integral heat is zero at 2–25°C for 45. 95 % by wt dioxane. The initial heats of solution of NaI at 25° in water and the mixtures are –1. 81, –4. 99, –5. 39, –6. 63 kcal/mole and bear a linear relation to the composition and dielectric constant of the solvent.     

13.

Tetrabutylammonium and Caesium Salts of Trinitromethane     

J. C. Bryan  M. N. Burnett  A. A. Gakh 《Acta Crystallographica. Section C, Structural Chemistry》1998,54(9):1229-1233

     

14.

Synthesis of perchloratocobaltates (II) of cesium,rubidium, and ammonium     

S. V. Loginov  Z. K. Nikitina  V. Ya. Rosolovskii 《Russian Chemical Bulletin》1977,26(7):1351-1355

     

15.

Synthesis of rubidium ozonide via rubidium superoxide     

Vol'nov  I. I.  Dobrolyubova  M. S.  Tsentsiper  A. B. 《Russian Chemical Bulletin》1966,15(9):1611-1611

Conclusions We were the first to obtain a high quality rubidium ozonide employing a new reaction between rubidium superoxide and ozonized oxygen.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 9, p. 1665, September, 1966.     

16.

Thermochemistry of copper(II) ion solvation in aqueous organic solvents     

S. V. Mikheev  V. A. Sharnin  V. A. Shormanov  M. N. Talanova 《Journal of Thermal Analysis and Calorimetry》1995,45(4):715-720

The integral heat effects of CuCl₂ dissolution in aqueous DMSO, aqueous ethanol and aqueous acetone solutions at 298. 15 K in the electrolyte concentration range 0.001–0.01M were measured by means of calorimetry. ΔH _sol ⁰ values were obtained by extrapolation to zero electrolyte concentration. Literature data were used to determine the thermodynamic characteristics of Cu²⁺ transfer from water to aqueous organic solvents.     

17.

Thermochemistry and structure of atoms     

A. F. Kapustinsky  M. S. Stakhanova 《Russian Chemical Bulletin》1954,3(4):501-510

     

18.

The benzoyl ion. Thermochemistry and kinetic energy release     

J. F. Elder  J. H. Beynon  R. G. Cooks 《Journal of mass spectrometry : JMS》1976,11(4):415-422

The thermochemistry of benzoyl ion formation from a variety of sources has been examined by using the measured kinetic energy release for metastable ions to estimate the excess energy of the activated complex. A correlation is observed between this estimated excess energy and literature values of the heat of formation of the benzoyl ion. From this relationship and the observed correlation between the uncorrected heat of formation and the difference between the appearance potential of [C6H5CO]⁺ and the ionization potential of the parent compound, the large range of reported values for ΔHf[C6H5CO]⁺ is seen to be due, at least in part, to variation in the kinetic shift with the critical energy of the reaction. With the exception of the ion generated from trifluoroacetophenone and possibly that from benzaldehyde, the fragmenting [C7H5O]⁺ ions are shown, from kinetic energy release data, to be structurally identical. The approach adopted here may have general merit in improving or testing the accuracy of thermochemical data based on appearance potential measurements.     

19.

Thermochemistry of Ketene     

Takhistov  V. V.  Ponomarev  D. A.  Golovin  A. V. 《Russian Journal of General Chemistry》2003,73(11):1774-1776

A new value, -100±10 kJ mol^{- 1}, was obtained for the enthalpy of formation of gaseous ketene, H _f ⁰(g)(CH₂ = C = O), from the data obtained by the authors in combination with certain published experimental and calculation data. The suggested value is considerably lower than the value accepted in the literature, -48 kJ mol^{- 1}.     

20.

Thermochemistry of lignin     

Yu. N. Sazanov  A. V. Gribanov 《Russian Journal of Applied Chemistry》2010,83(2):175-194

Thermochemical reactions occurring in various stages of structural transformations of native lignin in its thermal treatment in a wide temperature range are considered and classified. Attention is given to the initial state of lignin in its primary isolation without heating. The terminology of lignin products, used in the literature, is put in order to a certain extent. The thermochemical reactions in which lignins are transformed in processing of raw wood materials and the structure of isolated lignins undergoes changes in the course of the target thermal treatment are differentiated. The applied aspect of the directed thermochemical synthesis of new lignin-based low- and high-molecular-mass compounds is discussed.     

	$\text{ΔH}{}_{\mathrm{r}}\text{/kcal}{}_{\mathrm{th}}\text{mol}{}^{\mathrm{?1}}$	$\text{ΔH}{}_{\mathrm{f}}{}^{\mathrm{o}}\text{(c, 298.15 K)/kcal}{}_{\mathrm{th}}\text{mol}{}^{\mathrm{?1}}$
α-Li2UO4	?(41.77±0.02)	?(463.31±0.84)
K2UO4	?(42.07±0.05)	?(451.39±0.83)
Rb2UO4	?(41.30±0.05)	?(452.00±0.85)

Caesium salts of titanium,zirconium and thorium cyanoferrates(II)

The synthesis of cyanoferrates of quadrivalent metals and the sorption of caesium ions by these materials have been studied. It has been found that the compositions of the compounds and their properties are strongly influenced by the degree of hydrolysis of the metal. These is no sorption of caesium by Zr⁴⁺ and Th⁴⁺ cyanoferrates, while the compounds of oxygencontaining bivalent complex cations exhibit behaviour similar to that of the other bivalent metals. The sorption of caesium by (TiO)₂R is govermed by an ion-exchange mechanism; with (ZrO)₂R changes occur in the crystal lattice, and (ThO)₂R exhibits a low affinity towards caesium.     

Thermochemistry of decomposition of manganese(II) oxalate dihydrate

Differential scanning calorimetry (DSC) has been used to determine the enthalpy of dehydration of manganese(II) oxalate dihydrate and the enthalpies of decomposition in nitrogen and in oxygen of the anhydrous oxalate. The thermodynamic data have been related to the activation energies reported in kinetic studies and to the mechanisms proposed for the thermal decomposition and oxidation processes.     

Electronically excited rubidium atom in helium clusters and films. II. Second excited state and absorption spectrum

Following our work on the study of helium droplets and film doped with one electronically excited rubidium atom Rb(?) ((2)P) [M. Leino, A. Viel, and R. E. Zillich, J. Chem. Phys. 129, 184308 (2008)], we focus in this paper on the second excited state. We present theoretical studies of such droplets and films using quantum Monte Carlo approaches. Diffusion and path integral Monte Carlo algorithms combined with a diatomics-in-molecule scheme to model the nonpair additive potential energy surface are used to investigate the energetics and the structure of Rb(?)He(n) clusters. Helium films as a model for the limit of large clusters are also considered. As in our work on the first electronic excited state, our present calculations find stable Rb(?)He(n) clusters. The structures obtained are however different with a He-Rb(?)-He exciplex core to which more helium atoms are weakly attached, preferentially on one end of the core exciplex. The electronic absorption spectrum is also presented for increasing cluster sizes as well as for the film.     

Thermochemistry of thermal plasma chemical reactions. Part II. A survey of synthesis routes for silicon nitride production

Feasibility routes for thermal plasma production of silicon nitride powders are explored. First, a collation of the various proposed systems from the extant literature is examined. Reactant systems investigated include free silicon, silicon monoxide, silicon dioxide, silicon tetrachloride, silane, and other organosilicon precursors, along with various nitriding and reducing species. The reaction yields of these systems are brought to a common denominator by thermodynamic analysis and a first-step introduction of nucleation kinetics including comparisons against published experiments and the authors' own research. In particular, it is observed that the formation of liquid-phase free silicon in the neighborhood of 2500 K is quite detrimental to silicon nitride yield, and furthermore, a high supersaturation of silicon should always be avoided.     

Thermochemistry of Binding of Lead(II) and Cadmium(II) by Saccharides in Aqueous Solution

Solution calorimetry was used to determine enthalpies and stability constants for binding of lead(II) or cadmium(II) by galacturonic acid and several monosaccharides in aqueous solution. New values for enthalpies of solution in water are reported for galacturonic acid and maltose monohydrate. The interaction of water solvent with the reactants is the largest factor in the binding process.     

Thermochemistry of nonaqueous solutions of electrolytes: II. Heat of solution of sodium iodide in water-dioxane

The heats of solution of sodium iodide in water and water-dioxane (45. 95, 52. 55, and 68. 15% by wt dioxane at 25° (also for 2° for the first of these mixtures) are reported. The process becomes more exothermic as the dioxane content increases; a qualitative interpretation. The temperature coefficient of the integral heat is zero at 2–25°C for 45. 95 % by wt dioxane. The initial heats of solution of NaI at 25° in water and the mixtures are –1. 81, –4. 99, –5. 39, –6. 63 kcal/mole and bear a linear relation to the composition and dielectric constant of the solvent.     

Synthesis of rubidium ozonide via rubidium superoxide

Conclusions We were the first to obtain a high quality rubidium ozonide employing a new reaction between rubidium superoxide and ozonized oxygen.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 9, p. 1665, September, 1966.     

Thermochemistry of copper(II) ion solvation in aqueous organic solvents

The integral heat effects of CuCl₂ dissolution in aqueous DMSO, aqueous ethanol and aqueous acetone solutions at 298. 15 K in the electrolyte concentration range 0.001–0.01M were measured by means of calorimetry. ΔH _sol ⁰ values were obtained by extrapolation to zero electrolyte concentration. Literature data were used to determine the thermodynamic characteristics of Cu²⁺ transfer from water to aqueous organic solvents.     

The benzoyl ion. Thermochemistry and kinetic energy release

The thermochemistry of benzoyl ion formation from a variety of sources has been examined by using the measured kinetic energy release for metastable ions to estimate the excess energy of the activated complex. A correlation is observed between this estimated excess energy and literature values of the heat of formation of the benzoyl ion. From this relationship and the observed correlation between the uncorrected heat of formation and the difference between the appearance potential of [C6H5CO]⁺ and the ionization potential of the parent compound, the large range of reported values for ΔHf[C6H5CO]⁺ is seen to be due, at least in part, to variation in the kinetic shift with the critical energy of the reaction. With the exception of the ion generated from trifluoroacetophenone and possibly that from benzaldehyde, the fragmenting [C7H5O]⁺ ions are shown, from kinetic energy release data, to be structurally identical. The approach adopted here may have general merit in improving or testing the accuracy of thermochemical data based on appearance potential measurements.     

Thermochemistry of Ketene

A new value, -100±10 kJ mol^{- 1}, was obtained for the enthalpy of formation of gaseous ketene, H _f ⁰(g)(CH₂ = C = O), from the data obtained by the authors in combination with certain published experimental and calculation data. The suggested value is considerably lower than the value accepted in the literature, -48 kJ mol^{- 1}.     

Thermochemistry of lignin

Thermochemical reactions occurring in various stages of structural transformations of native lignin in its thermal treatment in a wide temperature range are considered and classified. Attention is given to the initial state of lignin in its primary isolation without heating. The terminology of lignin products, used in the literature, is put in order to a certain extent. The thermochemical reactions in which lignins are transformed in processing of raw wood materials and the structure of isolated lignins undergoes changes in the course of the target thermal treatment are differentiated. The applied aspect of the directed thermochemical synthesis of new lignin-based low- and high-molecular-mass compounds is discussed.