Transpiration vapour pressures and activities in the molten salt systems ZnCl2 + NaCl and ZnCl2 + KCl

1970 ◽  
Vol 23 (3) ◽  
pp. 501 ◽  
Author(s):  
H Bloom ◽  
TH Spurling ◽  
J Wong
Keyword(s):  
Zinc Chloride ◽  
Pressure Measurements ◽  
Complex Ions ◽  
Alkali Chloride ◽  
Independent Evidence ◽  
Unique Type ◽  
Form Complex ◽  
Transpiration Method ◽  
Salt Systems ◽  
Sodium And Potassium

Vapour pressure measurements were made by a transpiration method for molten zinc chloride and molten mixtures of this salt with sodium and potassium chlorides, respectively. Activities of zinc chloride in the mixtures were calculated and from these values, those of the alkali chloride were calculated by Gibbs-Duhem integration. For this purpose a convenient computer method has been devised. Although the large deviations of activity and activity coefficients qualitatively support independent evidence that complex ions are formed in these systems, the results cannot quantitatively be explained using a calculation due to Braunstein in terms of interactions in the melt to form complex ions of a unique type, e.g. ZnCl3- or ZnCl42- etc. This indicates that the departure from ideal behaviour needs to be explained by a more detailed theory.

Vapour pressures and activities in the reciprocal fused salt systems ZnCl2 + Na2SO4 and ZnSO4 + NaCl

1975 ◽  
Vol 28 (12) ◽  
pp. 2587 ◽  
Author(s):  
RG Anthony ◽  
H Bloom
Keyword(s):  
Zinc Chloride ◽  
Vapour Pressure ◽  
Reciprocal System ◽  
Covalent Bonding ◽  
Salt System ◽  
Log P ◽  
Complex Ions ◽  
Partial Molar Enthalpies ◽  
Salt Systems ◽  
Fused Salt

Zinc chloride vapour pressures, activities and partial molar energies have been determined in the reciprocal fused salt system: Zn,Na/Cl,SO4 over the range 770-900 K. The transpiration vapour pressure of pure ZnCl2 was first redetermined for the range 720-900 K and found to follow the equation (in which P� is in mmHg): �������������� Log P�ZnCl2 = (-8247�17)/T-5.033 log T + 26.213 � 0.006 Activities of ZnC1, in the reciprocal system differed greatly from ideality, the degree of departure varying with both composition and temperature. In general, at relatively high ZnCl, concentrations, observed activities were greater than ideal and ZnCl2 partial molar enthalpies were positive; this behaviour is believed to be largely caused by the effect of partial covalent bonding in pure ZnCl2. At low ZnCl2 concentrations, activities were much less than ideal and ZnCl2 partial molar enthalpies were negative; this other effect is believed to be caused by the formation of complex ions within this system.

Thermodynamic properties of the binary molten salt systems, PbBr2-KBr, PbBr2-RbBr and PbBr2-CsBr, by measurement of the electromotive forces of galvanic cells

1981 ◽  
Vol 34 (3) ◽  
pp. 479 ◽  
Author(s):  
H Bloom ◽  
MS White
Keyword(s):  
Thermodynamic Properties ◽  
Molten Salt ◽  
Activity Coefficients ◽  
Molten Salts ◽  
Free Energies ◽  
Complex Ions ◽  
Galvanic Cells ◽  
Salt Systems

The electromotive forces of galvanic cells for the formation of PbBr2 in the molten binary salt systems, PbBr2-KBr, PbBr2,-RbBr and PbBr2-CsBr, have been measured. Activities, activity coefficients and partial molar free energies have been calculated for each component of the three systems. Integral free energies of mixing have also been calculated. Various models of mixing of molten salts have been applied to the results. The systems contain complex ions, probably mixtures of PbBr42-, PbBr64- with some PbBr3-.

scholarly journals Tungsten Chemistry in Alkali Chloride Melts

2007 ◽  
Vol 62 (12) ◽  
pp. 739-744 ◽  
Author(s):  
Danil A. Danilov ◽  
Vladimir A. Volkovich ◽  
Boris D. Vasin ◽  
Ilya B. Polovov ◽  
Trevor R. Griffiths
Keyword(s):  
Chloride Ions ◽  
Carbon Anode ◽  
Complex Ions ◽  
Anodic Current ◽  
Alkali Chloride ◽  
Oxide Hydroxide ◽  
Chloride Melts ◽  
Current Densities ◽  
Tungsten Hexachloride ◽  
Oxide Ions

Speciation of tungsten in alkali chloride melts (based on NaCl-2CsCl, NaCl-KCl and 3LiCl-2KCl mixtures) was studied between 550 and 750◦C using electronic absorption spectroscopy. OnlyW(IV) and W(V) chloro and oxychloro species can be stabilized under the conditions studied. Tungsten(IV) chloride ions are very sensitive to oxide/hydroxide impurities present in the melt. Anodic dissolution ofWmetal at anodic current densities in the range of 0.005 - 0.1 A/cm2 produces only [WCl6]2− ions that can be electrochemically (on a glassy carbon anode) oxidized to [WCl6]−. Small amounts of oxide ions present in the melt result in a gradual conversion of W(IV) chloro species intoW(IV) oxychloro species. In the presence of O2 in the atmosphere [WCl6]2− is oxidized into the tungsten(V) species [WOCl5]2−. Dissolution of tungsten hexachloride, WCl6, in an NaCl-2CsCl melt initially yields [WCl6]2− (due to disproportionation). Reaction of metallic tungsten with Pd(II)-containing melts results in the formation of [WCl6]2− species. The main spectroscopic parameters of [WCl6]2− and [WCl6]− complex ions were calculated.

Vapour pressure measurements on lanthanum polyphosphate and ultraphosphate by the transpiration method

2013 ◽  
Vol 61 ◽  
pp. 147-153 ◽  
Author(s):  
Naoyuki Hatada ◽  
Kazuaki Toyoura ◽  
Yoshitaro Nose ◽  
Tetsuya Uda
Keyword(s):  
Vapour Pressure ◽  
Pressure Measurements ◽  
Transpiration Method

scholarly journals Trace element accumulation by soils and plants in the North Caucasian geochemical province

2021 ◽  
Vol 247 ◽  
pp. 1-13
Author(s):  
Vladimir Alekseenko ◽  
Natalya Shvydkaya ◽  
Jaum Bech ◽  
Alexander Puzanov ◽  
Aleksey Nastavkin
Keyword(s):  
Chemical Elements ◽  
Complex Ions ◽  
Ionic Radii ◽  
Regional Patterns ◽  
Form Complex ◽  
The North ◽  
Low Concentrations ◽  
Long Term Studies ◽  
Geochemical Province

Long-term studies of the North Caucasian geochemical province allowed to establish regional abundances and calculate accumulation (dispersion) factors for chemical elements in rocks, soils, and plants. Certain natural regional patterns characterize the province. Associations of elements in high and low concentrations are often determined by the predominant composition of rocks: carbonate-terrigenous, terrigenous, and igneous. The study of the average contents of several chemical elements in the soils of the province showed that the association of accumulated elements includes metals with different migration characteristics. Thus, despite the rather close values of the ionic radii, Pb, Zn, Cu, and Li (judging by the ionic potential) are characterized by the formation of cations, while Mn, Mo, and Zr form complex ions. Such elements as Zn, Cu, and Pb are mainly accumulated on hydrosulfuric barriers, while Mo, Co, and Mn are stopped by oxygenous barriers. For Cu, Zn, Mo, and Co, biogenic accumulation plays a significant role, while for Pb and Ni it is practically absent. The absolute dispersion of the elements did not reach environmentally hazardous values, although it indicates a fairly intensive migration. In woody plants, Ba, Nb, Sc, Sr, and Zn are accumulated most intensively. 

Molten salt mixtures. XI. Integral and partial molar volumes in the molten salt systems PbCl2 + NaCl, PbCl2 + RbCl, PbCl2 + CsCl, CdCl2 + RbCl, and CdCl2 + CsCl

1966 ◽  
Vol 19 (9) ◽  
pp. 1591 ◽  
Author(s):  
H Bloom ◽  
PWD Boyd ◽  
JL Laver ◽  
J Wong
Keyword(s):  
Molten Salt ◽  
Molar Volume ◽  
Partial Molar Volume ◽  
Binary Systems ◽  
Partial Molar Volumes ◽  
Complex Ions ◽  
Molar Volumes ◽  
Temperature Range ◽  
Salt Mixtures ◽  
Salt Systems

The densities of molten PbCl2, CsCl, and RbCl and of the molten salt systems PbCl2 + NaCl, PbCl2 + RbCl, PbCl2 + CsCl, CdCl2 + RbCl, and CdCl, + CsCl have been measured to an accuracy of �0.1% by an Archimedean method over a considerable temperature range. Integral and partial molar volume isotherms have been constructed for the above binary systems and are interpreted to show that complex ions are formed in all but the PbCl2+NaCl system.

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