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1.
《Journal of Inorganic and Nuclear Chemistry》1978,40(11):1903-1905
The solubility equilibria between Cd(II) and 2-mercaptoproprionic acid in 3.0 M NaClO4 at 25°C have been studied by e.m.f. The e.m.f. measurement with both glass and Cd(Hg) electrodes in the range 2.5 < pH < 4.8 were made in solutions where a solid phase coexists with soluble complexes CdqAp. Free ligand and metal ion concentrations were calculated in order to determine the solubility product of CdA (eqn 5). From the values of the formation constants for the soluble complexes and the solubility product, the solubility constants kspq have been computed. A general equation for the redissolution of the precipitate is proposed and a set of equilibrium constants is given. 相似文献
2.
F. Hernández-Luis M. Barrera H. R. Galleguillos L. Fernández-Mérida M. Pérez 《Journal of solution chemistry》1996,25(2):219-229
The activity coefficients of sodium bromide in the ternary system NaBr+NaClO4+H2O were determined at 25°C and constant ionic strength of 0.1, 0.5, 1, 2, and 3 mol-kg?1 from emf of the cell without, liquid junction $$ISE - Na|NaBr(m_A ), NaClO_4 (m_B ), AgCl_{(s)} 1 Ag$$ The experimental activity coefficients were comparatively analyzed by using the Harned, Scatchard, Pitzer and Lim-HOLL treatments. All these methods are adequate for the analysis of the experimental data. The results have been compared with those of Lanier for the system: NaCl+NaClO4+H2O. The Gibbs excess energy of mixing was obtained and qualitatively interpreted in terms of ionic interactions. 相似文献
3.
4.
Jesús M. Arsuaga Fernando Fernández-Martín Javier Núñez 《Journal of solution chemistry》1996,25(2):167-177
The enthalpies of dilution for aqueous solutions of [Co(en)3]Cl3, where en=1,2-diaminoethane, have been measured at 25°C, and up to m=1 mol-kg–1, using a new large isoperibol calorimeter by the long-jump method. Relative apparent molar enthalpies L have been extracted as an empirical equation relating L and m. Comparison with other 31 and 13 aqueous systems confirms the previously suggested hydrophobic character of the [Co(en)3]3+ cation. 相似文献
5.
6.
Résumé The standard partial molar volumes have been determined for [(en)2ClCo(III)(don) Co(III)CL(en)2] Br4-[-CDX]-rotaxane (Rotaxane) and its component compounds, [(en)2ClCo(III)(don)Co(III)Cl(en)2] Br4 (Co(III)-II), and -CDX, in aqueous solution at 25°C Vo (Rotaxane) is smaller than the sum of Vo (CO(III)-II) and Vo (-CDX) by about 28 cm3-mol–1. Some estimations were attempted; the number of methylene groups in the cavity of -CDX, was estimated to be six and the number of water molecules expelled from -CDX cavity by hydrocarbon chain of the Rotaxane, is around four. 相似文献
7.
O. M. Polishchuk A. A. Fakeev N. B. Krasnova A. G. Vendilo 《Russian Journal of Inorganic Chemistry》2012,57(3):458-461
Solubility in the KNO3-Cr(NO3)3-H2O system at 25°C was studied by an isothermal method. The existence of solid phases of potassium nitrate and chromium(III)
nitrate nonahydrate was confirmed by constructing a phase diagram, chemical analysis, and IR spectroscopy. Crystallization
of potassium nitrate from aqueous solutions was studied. Potassium nitrate does not interact with chromium(III) nitrate within
the range of micro and macro concentrations. The capture of chromium(III) by KNO3 crystals is due to adsorption and occlusion of a mother solution. 相似文献
8.
The conductivity of salicylic acid in methanol-water mixtures was measured at 25 °C. Experimental data were analyzed using the Hsia-Fuoss and Fuoss-78 conductance equations and a comparison was made. The Hsia-Fuoss and Fuoss-78 methods were also used to deter-mine the thermodynamic association constants and the limiting molar conductivities for all solvent compositions. The limiting equivalent conductance decreases with an increase in the methanol content in the binary mixtures over the whole range of solvent compositions, but the variation does not give a constant value of Walden product. The electrolytes were found to be practically completely associated in all solvent mixtures studied. The association constant of salicylic acid decreases as the dielectric constants of the mixtures increase. 相似文献
9.
Fe(III) hydrolysis and fluoride complexation behavior was examined in 0.68 molal sodium perchlorate at 25°C. Our assessment of the complexation of Fe(III) by fluoride ions produced the following results: logF1 = 5.155, logF2 = 9.107, logF3 = 11.96, logF4 = 13.75, where logFn = 5.155=[FeF
n
(3-n)+
][Fe3+]–1[F–]–n. The stepwise fluoride complexation constants,FK
n+1, obtained in our work (where logF
K
n+1 =logFn) indicate that K
n+1/K
n
=0.072±0.01. Formation constants for equilibria, Fe3++nH2OFe(OH)
n
(3–n)+
+nH+, expressed in the form
n
*
[Fe(OH)
n
(3-n)+
][H+]n
,[Fe
3+]-1, were estimated as
1
*
= –2.754, and
2
*
–7. Our study indicates that the results of previous hydrolysis investigations include very large overestimates of Fe(OH)
2
+
formation constants. 相似文献
10.
Th. Fanghänel Th. Könnecke H. Weger P. Paviet-Hartmann V. Neck J. I. Kim 《Journal of solution chemistry》1999,28(4):447-462
The carbonate complexation reactions of Cm(III) were studied by time-resolved laser fluorescence spectroscopy in 0–6 m NaCl at 25°C. The ionic strength dependence of the stepwise formation constants for the carbonato complexes Cm(CO3)
n
3–2n
with n = 1, 2, 3, and 4 is described by modeling the activity coefficients of the Cm(III) species with Pitzer's ion-interaction approach. Based on the present results and literature data for Cm(III) and Am (III), the mean carbonate complexation constants at I = 0 are calculated to be: log
101
o
=8.1 ±0.3, log
102
o
=13.0 ± 0.6, log
103
o
=15.2 ± 0.4, and log
104
o
=13.0 ± 0.5. Combining these equilibrium constants at infinite dilution and the evaluated set of Pitzer parameters, a model is obtained, that reliably predicts the thermodynamics of bivalent actinide An(III) carbonate complexation in dilute to concentrated NaCl solution. 相似文献
11.
R. Sh. Erkasov R. M. Nesmeyanova R. S. Orazbaeva S. M. Bolysbekova 《Russian Journal of Inorganic Chemistry》2013,58(2):213-215
The ZnCl2-CO(NH2)2-HCl-H2O quaternary system at 25°C was studied by the solubility method. The concentration boundaries of crystallization were established for the phases that correspond to the eutonic compositions of ternary systems, for double carbamide compounds with zinc chloride and hydrochloric acid, and for the compound ZnCl2 · 2CO(NH2)2 · HCl. 相似文献
12.
M. M. Godneva V. Ya. Kuznetsov M. P. Rys’kina V. V. Semushin N. L. Mikhailova 《Russian Journal of Inorganic Chemistry》2014,59(8):849-857
Phase formation in the ZrO(NO3)2-NaF(HF)-H3PO4-H2O system was studied at 20°C and 2.0–14.5 wt % ZrO2 in the initial solution along sections with molar ratios PO 4 3? /Zr = 0.5 and 1.5 and also in the presence of hydrogen fluoride at Na/Zr = 1 and PO 4 3? /Zr = 0.5, 1.0, and 1.5. Crystalline zirconium hydrophosphate Zr(HPO4)2 · H2O, fluorozirconates Na5Zr2F13 and Na7Zr6F31 · 12H2O, fluorophosphatozirconates NaH2Zr3F3(PO4)4 · 3H2O and NaZr2F6(PO4) · 4H2O, and amorphous NaZrO0.5F(PO4) · 4H2O (provisional composition) were separated at room temperature. NaH2Zr3F3(PO4)4 · 3H2O and NaZr2F6(PO4) · 4H2O were prepared for the first time and were studied by crystal-optical, elemental, and thermal analyses, X-ray powder diffraction, IR spectroscopy, scanning electron microscopy (SEM), and X-ray microanalysis. Na7Hf6F31 · 12H2O was found to exist in a mixture with the hydrophosphate. 相似文献
13.
Sh. Sh. Khamdamova 《Russian Journal of Inorganic Chemistry》2017,62(11):1520-1524
Solubility in ternary aqueous systems including calcium chlorate and diethanolamine (triethanolamine) has been studied at 25°C. Solubility diagrams have been constructed. Solubility curves consist of three branches corresponding to the crystallization of calcium chlorate, diethanolamine (triethanolamine), and compound Ca(ClO3)2 · NH(C2H4OH)2 or Ca(ClO3)2 · N(C2H4OH)3. The compounds have been isolated and identified by chemical analysis, X-ray powder diffraction, and thermal analysis. 相似文献
14.
J. N. Spencer J. E. Mihalick Ian M. Paul Bhakti Petigara Zhenqing Wu Shuyun Chen C. H. Yoder 《Journal of solution chemistry》1996,25(8):747-756
Complexation between -cyclodextrin (-CD) and aliphatic amines in water and DMF solvents was studied by calorimetry. Amines form complexes with -CD in both solvents but the nature of the complexes is quite different. In DMF the amines donate a hydrogen from the amine N–H group to the cyclodextrin forming a normal hydrogen bonded complex. In DMF solutions with large amine concentrations, complexes other than 11 are observed. In contrast, in aqueous environment the amines form inclusion complexes in which the amine alkyl group penetrates the -CD cavity and is stabilized by van der Waals interactions. The equilibrium constants for the complexes formed in water solvent increase with increasing alkyl chain length due to an entropy effect. 相似文献
15.
Ternary mutual diffusion coefficients (D11, D22, D12 and D21) measured by the Taylor dispersion method are reported for aqueous solutions of {levodopa (l-dopa) + HCl} solutions at 25 °C and HCl concentrations up to 0.100 mol · dm−3. The coupled diffusion of l-dopa (1) and HCl (2) is significant, as indicated by large negative cross-diffusion coefficients. D21, for example, reaches values that are larger than D11, the main coefficient of l-dopa. Combined Fick and Nernst–Planck equations are used to analyze the proton coupled diffusion of l-dopa and HCl in terms of the binding of H+ ions to l-dopa and ion migration in the electric field generated by l-dopa and HCl concentration gradients. 相似文献
16.
L. S. Grigor’eva 《Russian Journal of Inorganic Chemistry》2014,59(8):858-860
The lanthanum trichloroacetate-lanthanum perchlorate-water ternary system was studied by the isothermal solubility method at 25°C. The compositions of solid phases were studied by the Schreinemakers method. The refraction indices, specific volumes, and viscosities of liquid phases were determined. The crystallization of the initial components and, the formation of a closed area of solid solutions were established in the system. 相似文献
17.
Joana Monterrosa José Daniel Martínez Mary Lorena Araujo Felipe Brito Giuseppe Lubes Mildred Rodríguez Lino Hernández Vito Lubes 《Journal of solution chemistry》2012,41(4):589-598
We studied speciation of the mixed-ligand complex formation equilibria of vanadium(III) with both 2,2??-bipyridine (Bipy) and the amino acids glycine (HGly), proline (HPro), ??-alanine (H??Ala), and ??-alanine (H??Ala) by means of electromotive forces measurements emf(H) using 3.0?mol?dm?3 KCl as the ionic medium at 25 °C. The experimental data were analyzed by means of the computational least-squares program LETAGROP, taking into account the hydrolysis of the vanadium(III) cation, the respective stability constants of the binary complexes, and the acid/base reactions of the ligands which were kept fixed during the analysis. In all four amino acid systems studied we observed the complexes [V2O(Bipy)(B)]3+, [V2O(Bipy)2(B)2]2+, [V(OH)(Bipy)(B)2] and [V(OH)2(Bipy)(B)], where B represents the deprotonated form of the amino acids studied in this work. The respective stability constants were determined and the species distribution diagrams as a function of pH are briefly discussed. 相似文献
18.
Francesco Malatesta Sara Trombella Nicolangelo Fanelli 《Journal of solution chemistry》2000,29(8):685-699
The relative activity coefficients of MnSO4 and Mn(ClO4)2 were measured downto about 5×10–5 mol-kg–1 by means of cells with ion-exchange liquid membranes.The measurements at high dilution provide an answer to the age-old problem ofabsolute values of the activity coefficients for MnSO4. They also lead to acorrection of the activity coefficients for Mn(ClO4)2, whose literature values arefound to be biased by ca. 6.5%. Like other bivalent metal sulfates, MnSO4does not obey the Debye—Hückel law inasmuch as negative instead of positivedeviations from the limiting law are observed in the dilute regions. The possibilityfor this kind of behavior to denote ion association is discussed. The best-fitparameters of Pitzer's equation, able to provide accurate values of the activityand osmotic coefficients of the two salts for any concentration, are reported. 相似文献
19.
The viscosity of dilute aqueous solutions of K3[AI(ox)3]·3H2O, K3[Fe(ox)3]·3H2O, K3[Co(ox)3]·3H2O, and K3[Cr(ox)3]·3H2O complexes, as well as K2(ox)·H2O, were measured between 15 and 35°C. Those of CoCl2, 6H2O, FeCl3, A12(SO4)3·18H2O, and CrCl3·6H2O were measured at 25°C. These data were analyzed by the Jones–Dole equation. The ionic B coefficients of the above complex anions were discussed in terms of ion–solvent interactions and the overall change in B associated with complex formation. 相似文献
20.
The osmotic and activity coefficients of aqueous sodium and potassium methyl sulfates have been determined at 25°C by the isopiestic method, in the molality range from ca.0.2 to 25 and 19 mol-kg–1, respectively. The results have been discussed in terms of the ion–ion and ion–water interactions on the basis of the Pitzer and Mayorga model and a method developed in our laboratory. 相似文献