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1.
J. M. Simonson R. N. Roy D. Mrad P. Lord L. N. Roy D. A. Johnson 《Journal of solution chemistry》1988,17(5):435-446
Potentials for the cell without liquid juction
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2.
H. R. Galleguillos-Castro F. Hernández-Luis L. Fernández-Mérida M.A. Esteso 《Journal of solution chemistry》1999,28(6):791-807
Activity coefficients for sodium chloride in the NaCl + Na2SO4 + H2O ternary system were determined from emf measurements of the cell
3.
A high pressure UV-visible spectrophotometer was used to determine the dissociation constant of boric acid using an indicator technique. The measurements were made at 25°C and at ionic strengths of 0.1 and 1.0m over a pressure range of 1 to 2000 atm. Extrapolation to I=0 gave a thermodynamic dissociation constant of 5.16×10–10 at 1 atm. The pressure dependence yielded a partial molal volume change of –28.9 and –31.8 cm3-mol–1 and a compressibility change of –3.1 and –4.8×10–3 cm3-mol–1-atm–1 for the dissociation at I=0.1 and 1.0m, respectively. The association constant for the formation of the sodium borate ion pair was determined by comparing the acid constants in tetramethylammonium chloride to those in sodium chloride solutions. Extrapolation to I=0 yielded a KA for [NaB(OH)4] of 0.64 at 1 atm. The pressure dependence of KA gave
and
for the formation of the ion pair. 相似文献
4.
Results are given of the chemical modification of silicas containing
and
groups on their surface by pyridimidines in the gaseous phase. IR spectroscopy and field desorption mass spectrometric methods were used to obtain information on the structure of the surface compounds prepared. Possible reaction schemes are suggested. The high hydrolytic stability of some of the immobilized hydroxypyrimidines has been established.Translated from Teoreticheskaya i Éksperimental'naya Khimiya, Vol. 22, No. 4, pp. 495–499, July–August, 1986. 相似文献
5.
A method to determine activity coefficients of electrolytes in mixed solvent is described which makes use of ion-selective electrode(s) (ISE) and in which a concentrated electrolyte solution is continuously added. Activity coefficients for HCl in methanol-water mixtures containing 0, 10, 20, 30, 50, 70, and 90 weight percent methanol at 25, 35 and 45°C were calculated using the Pitzer equation, and the electromotive force (emf) data of the cell:
The experimental results agree well with literature values indicating that the proposed method is procise and reliable. 相似文献
6.
Solubility of Oxygen in Some 1-1, 2-1, 1-2, and 2-2 Electrolytes as a Function of Concentration at 25°C 总被引:1,自引:0,他引:1
The solubility of oxygen has been measured in a number of electrolytes [(LiCl, KCl, RbCl, CsCl, NaF, NaBr, NaI, NaNO3, KBr, KI, KNO3, CaCl2, SrCl2, BaCl2, Li2SO4, K2SO4, Mn(NO3)3)] as a function of concentration at 25°C. The solubilities, mol (kg-H2O)–1, have been fitted to a function of the molality m (standard deviation < 3mol-kg–1)
7.
Conditional stability constants of 2-[bis(2-hydroxyethyl)amino]-2(hydroxymethyl)-1,3-propanediol (BT) complexes of trivalent rare earth element (Ln) ions (La, Nd, Eu, Gd, Yb, Dy, Er, Lu) and Y were determined potentiometrically in aqueous NaCl solutions at 30°C and 0.1 M ionic strength. Least-squares fitting shows that, at <0.04 molal BT, the complex LnBT3+ is dominant, with LnBT2
3+ forming a secondary complex, where:
8.
Dontsova E. V. Lukov V. V. Kogan V. A. Popov L. D. 《Russian Journal of Coordination Chemistry》2003,29(9):639-642
The binuclear complexes of Cu2+ and Ni2+ with a new ligand system obtained through condensation of amino alcohols with 2-phenylhydrazone 1-phenylbutane-1,2,3-trione were synthesized. The compositions and structures of ligands and complexes were determined using elemental analysis, IR and NMR spectroscopy and magnetochemistry. The nickel complexes were found to be diamagnetic; in the copper complexes, substantial antiferromagnetic exchange interaction was observed (for Cu2+ complexes with n = 2 and 3, 2J is equal to –396 and –393 cm–1, respectively). The structure of the exchange fragment
is discussed. 相似文献
9.
The ultraviolet absorbance data from experiments conducted at constant pH and total iron concentration but variable B(OH)3 concentration were used to determined the stability constants of FeB(OH)
4
2+
and Fe[B(OH)4
2
+
at 25°C and an ionic strength of 0.68. The estimates obtained were *1 = 1.0 ± 0.2 × 10–2 and *2 = 2 ± 1 × 10–5, respectively (uncertainties are two times the standard error of the estimates). A calculation of the extent of iron(III) borate formation in ocean water at pH 8.2 shows that iron(III) borates are not a significantly large component of iron(III) speciation in seawater. 相似文献
10.
Carbonate stability constants for yttrium and all rare earth elements have been determined at 25°C and 0.70 molal ionic strength by solvent exchange and inductively coupled plasma–mass spectrometry (ICP–MS). Measured stability constants for the formation of
and
from M3+ are in good agreement with previous direct measurements, which involved the use of radio-chemical techniques and trivalent ions of Y, Ce, Eu, Gd, Tb, and Yb. Direct ICP–MS measurements of
and
formation constants are also in general agreement with modeled stability constants for the metals La, Pr, Nd, Sm, Dy, Ho, Er, Tm, and Lu, based on linear-free energy relationship (LFER). The experimental procedures developed in this work can be used for assessing the complexation behavior of other geochemically important ligands such as phosphate, sulfate, and fluoride. 相似文献
11.
Zusammenfassung Durch Reduktion von Dialkylamiden der diastereomeren 3-Anilino- und 3-Amino-2,3-diphenylpropansäuren mit LiAlH4 wurde die stereospezifische Synthese von 1-Anilino-bzw. 1-Amino-3-dialkylamino-1,2-diphenylpropanen verwirklicht. Die Konfiguration der erhaltenen Verbindungen wurde durch spektralanalytische Aussagen über den Charakter der Wasserstoff-brückenbindung vom Typ
bestätigt.Mit 1 Abbildung 相似文献
12.
The rates of oxidation of Fe(II) in NaCl and NaClO
4
solutions were studied as a function of pH (6 to 9), temperature (5 to 25°C), and ionic strength (0 to 6m). The rates are second order with respect to [H+] or [OH–] and independent of ionic strength and temperature. The overall rate of the oxidation is given by
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