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本文用高精度数字式振荡管密度计测定了288K至318K温度范围内Li2SO4 + Na2SO4 + H2O和 Li2SO4 + K2SO4 + H2O三元体系的密度。混合溶液的离子强度范围从0.1到4.5 mol.kg–1,混合溶液中Na2SO4和K2SO4的离子强度分数为0.2,0.4,0.6和0.8。用密度实验值拟合得到了不同温度下Pitzer离子相互作用模型混合参数θV和 ψV,模型的计算值与实验值的偏差在±0.002 g.cm–3以内。用Pitzer模型计算了不同离子强度下三元体系的混合体积。 相似文献
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本文续前报在恒定溶液总离子强度I=1.00mol·kg~(-1),改变葡萄糖在混合溶液中的质量百分数x=5%、15%和20%的条件下,应用电动势法测定了无液接界电池(A)和电池(B)的电动势: Pt,H_2(1.013×10~5Pa)|HCl(m),d-Glucose(x),H_2O(1-x)|AgCl-Ag (A) Pt,H_2(1.013×10~5Pa)|HCl(m_A),NaCl(m_B),d-Glucose(x),H_2O(1-x)|AgCl-Ag(B) 其中x代表葡萄糖在水中的质量百分数,m_A和m_B分别是HCl和NaCl在混合溶液中的质量摩浓度。利用电池(A)的电动势数据得到了AgCl-Ag电极在d-Glucose-H_2O混合溶液中的标准电极电势Φ_m~0,讨论了HCl的迁移性质,利用电池(B)的电动势数据,确定了HCl在HCl-NaCl-d-Glucse-H_2O体系中的活度系数γ_A,实验结果表明:在恒定总离子强度下,HCl的活度系数服从Harned规则。HCl的迁移自由能与葡萄糖的质量百分数x成线性关系。计算了HCl 相似文献
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The thermodynamic properties of HCl-NaCl-d-Glueose-H_2O system was studied by emf measurement without liquid junction. Pt, H_2(1.013×10~5 Pa)|Hel(m), d-Glucose(x), H_2O(1-x)| Agel-Ag (A) Pt, H_2(1.013×10~5Pa)|HCl(m_A), NaCl(m_B), d-Glucose(x), H_2O(1-x)|AgCl-Ag (B) at the mass percentage of d-Glucose x=5%, 15% and 20% in the mixed solution, from 5 to 45 ℃, for cell (B) at constant total ionic strength I=1.00 mol·kg~(-1). The standard electrode potential of Ag-AgCI in the mixed solution have been determined from cell (A). The activity coefficients of HCl, γ_A, in the mixed solution system have been determined from cell (B). The results show that the activity coefficients of HCl in HCl-NaCl solutions still obeye Harned Rule. The standard transfer Gibbs free energies of HCl have calculated. The primary, secondary and total medium effect of HCl have been calculated. 相似文献
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用分光光度法在293±1K温度下测定了由高价阳离子Fe~(3+)和高价阴离子(CTS)~(4-)(3,6-二磺酸钠-1,8-二羟基萘酚)形成配阴离子Fe(CTS)~(-)在乙醇-水混合溶剂中的稳定常数随离子强度的变化.用推广的Debye-H ckel方程和Pitzer方程计算了配位离子的热力学稳定常数,发现De-bye-H ckel方程完全不能适用本体系,而基于Pitzer方程的多项式逼近法则可得到满意的结果。讨论了介质效应和络合反应的标准迁移自由能。 相似文献
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用分光光度法于295±1K温度下测定了由高价阳离子Fe3+和高价阴离子tiron4-(3,5-二磺酸基邻苯二酚)形成的配阴离子Fe(tiron)-在乙醇-水混合溶剂中的稳定常数随离子强度的变化。分别用推广的Debye-Hückel方程和Pitzer方程计算了配阴离子的热力学稳定常数,发现对本体系De-bye-Hückel方程完全不能适用,而基于Pitzer方程的多项式逼近法则可得到满意的结果。讨论了介质效应和配合反应的标准迁移自由能。 相似文献
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在278.15~343.15 K温度范围内, 测定了在浓度范围从摩尔分数0.09的四氟硼酸-1-甲基-3-戊基咪唑(PMIBF4)离子液体水溶液到纯离子液体的密度, 计算了离子液体PMIBF4水溶液的表观摩尔体积fV, 讨论了Pitzer-Simonson (PS) 理论和Pitzer-Simonson-Clegg (PSC)理论的适用性. 以纯离子液体为参考态, 用实验数据分别拟合了Pitzer-Simonson (PS)方程、Pitzer-Simonson-Clegg (PSC)方程和简化PSC方程, 得到了这些理论模型的体积参数值. 从拟合偏差来看, PSC方程比PS方程有更好的适用性. 同时还可看出, PSC方程比只有三个参数的简化PSC方程有更小的拟合标准偏差和更好的相关系数. 相似文献
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Mariano Velázquez-Rivera Donald A. Palmer Richard M. Kettler 《Journal of solution chemistry》2006,35(12):1699-1730
This study measures the osmotic coefficients of {xH2SO4 + (1−x)Fe2(SO4)3}(aq) solutions at 298.15 and 323.15 K that have ionic strengths as great as 19.3 mol,kg−1, using the isopiestic method. Experiments utilized both aqueous NaCl and H2SO4 as reference solutions. Equilibrium values of the osmotic coefficient obtained using the two different reference solutions
were in satisfactory internal agreement. The solutions follow generally the Zdanovskii empirical linear relationship and yield
values of a
w for the Fe2(SO4)3–H2O binary system at 298.15 K that are in good agreement with recent work and are consistent with other M2(SO4)3–H2O binary systems. 相似文献
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Rabindra N. Roy James J. Gibbons Jonathan K. Trower Gregory A. Lee 《Journal of solution chemistry》1980,9(7):535-551
Activity coefficients of hydrochloric acid in mixed solutions of manganous chloride at twelve ionic strengths, from 0.1 to 5.0 mole-kg–1, were obtained from emf measurements of cells without liquid junction at five temperatures from 5 to 45°C. The data were interpreted in terms of the simple and convenient Pitzer treatment. Activity coefficients for manganous chloride in the mixtures were also derived using Pitzer's equations. Hydrochloric acid follows Harned's rule fromI=0.1 to 3.0 mole-kg–1, as concluded by Downes, whereas quadratic terms are warranted fromI=3.5 to 5.0 mole-kg–1. Contrary to Downes' conclusion, Harned's rule clearly does not hold true for manganous chloride at most ionic strengths. 相似文献
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Activity coefficients of hydrochloric acid have been determined from electromotive-force measurements of cells containing mixtures of hydrochloric acid and calcium chloride at constant total ionic strengthsI=0.1, 0.5, 1.0, 2.0, and 3.0 mole-kg–1 at 298.15°K. Interpretations based on Scatchard's and Pitzer's equations indicate that Pitzer's equations probably provide a more convenient guide to the thermodynamic properties of the mixed-electrolyte solutions. Activity coefficients for calcium chloride were derived from these equations. 相似文献
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Activities of water in the K2SO4+Rb2SO4+H2O system at 25°C have been measured isopiestically. On the basis of the experimental activities of water ternary parameters of the Pitzer equations have been calculated. According to our data and experimental solubility data from the literature, continous solid solutions between K2SO4 and Rb2SO4 are formed in this system. With the use of the Guggenheim polynomial for simulating excess functions of solid solutions on the basis of the original and literature solubility data, excess Gibbs energies of solid solution formation as well as a solubility diagram have been calculated. Results of the solubility calculation are in good agreement with experimental data. 相似文献
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通过循环伏安(CV)与电化学阻抗谱(EIS)测试研究了Ti基IrO2系活性涂层电极在含甲醇、甲酸及甲醛三种有机小分子的Na2SO4溶液中的电化学活性,其中以电极/溶液界面的双电层电容来表征电极的活性.结果表明,与同浓度H2SO4溶液相比,该电极在Na2SO4溶液中的电化学活性发生明显下降.有机小分子的加入降低了电极的活性表面积.发现有机物能在较宽的电位范围内发生氧化反应,但在该种电极上的电氧化速率较慢.然而,伴随着析氧反应的发生,有机物的氧化也随之加快. 相似文献
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Pavel Ya. Tishchenko Alexander S. Bychkov Andrea Hrabéczy-Páll Klára Tóth Ernö Pungor 《Journal of solution chemistry》1992,21(3):261-274
The mean activity coefficients of NaCl in the system NaCl+Na2SO4+H2O at various compositions were determined in the temperature range 5–45°C from the emf of potentiometric cells. By processing the results using Pitzer's equations the mixing parameters describing the non-ideal behavior of electrolytes were calculated. The temperature coefficients of the mixing parameters were determined and found not to be significant. The mixing parameters and temperature coefficients calculated for the binary mixture can be used to describe the behavior of multicomponent systems containing NaCl and Na2SO4, and eventually sea water. 相似文献
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The ionic liquid 1‐butyl‐3‐methylimidazolium hydrogensulfate, [bmim]HSO4, turned out to be resistant even to strong oxidizers like SO3. Thus, it should be a suitable solvent for the preparation of polysulfates at low temperatures. As a proof of principle we here present the synthesis and crystal structure of K2(S2O7)(H2SO4), which has been obtained from the reaction of K2SO4 and SO3 in [bmim]HSO4. In the crystal structure of K2(S2O7)(H2SO4) (orthorhombic, Pbca, Z = 8, a = 810.64(2) pm, b = 1047.90(2) pm, c = 2328.86(6) pm, V = 1978.30(8) Å3) two crystallographically unique potassium cations are coordinated by a different number of monodentate and bidentate‐chelating disulfate anions as well as by sulfuric acid molecules. The crystal structure consists of alternating layers of [K2(S2O7)] slabs and H2SO4 molecules. Hydrogen bonds between hydrogen atoms of sulfuric acid molecules and oxygen atoms of the neighboring disulfate anions are observed. 相似文献
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B. B. Damaskin 《Russian Journal of Electrochemistry》2006,42(9):990-994
Based on the results of the regression analysis of differential capacitance curves of a mercury electrode in solutions of cyclobutane carboxylic acid (CBCA) at 25, 50, and 75°C, the adsorption parameters that enter into both the Frumkin isotherm and the model of two parallel capacitors are estimated. The free energies of adsorption found from the analysis of the temperature dependence of these parameters are incorrect due to the partial blowing out of CBCA during the deaeration of the solutions. The corresponding adsorption parameters are corrected under the assumption that the hydrophobic effect associated with the increase in the liquid-water entropy at the removal from it of CBCA molecules is the same as for n-valeric acid. The physical meaning of the squeezing-out effect is revised. 相似文献
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Rabindra N. Roy James J. Gibbons David P. Bliss Jr. Richard G. Casebolt Bradley K. Baker 《Journal of solution chemistry》1980,9(12):911-930
Electromotive-force measurements have been made on HCl–MgCl2–H2O mixtures at 5, 15, 25, 35 and 45°C at eleven different ionic strengths from 0.1–5.0 mol-kg
–1
. The results are interpreted in terms of the simple Harned's equations, as well as the more complicated Pitzer ion-component treatment of multicomponent electrolyte mixtures. Activity coefficients for HCl in the salt mixtures obey Harned's rule up to and including I=5.0. For the salt in the acid mixtures, Harned's rule holds true up to and including I=0.5. The contribution of higher-order electrostatic terms (E and E') in the Pitzer equations is important for accurate evaluations of unlike cation-cation interactions (H,Mg), and cation-anion-cation interactions (H,Mg,Cl). The values ofSH,Mg and H,Mg,Cl (determined with E and E'), H,Mg and H,Mg,Cl (determined without E and E'), as well as the trace activity coefficients of HCl,
tr
A
, in solutions of MgCl2 (where ionic strength fraction of the salt,y
B = 1) at all the experimental temperatures and ionic strengths, are reported. Results of this study are compared with those for similar systems. At I=0.1 and 25°C, the results of the Brönsted-Guggenheim specific interaction theory are discussed briefly. 相似文献
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采用循环伏安、线性扫描、交流阻抗等技术研究了Ce3+/Ce4+电对在混酸(硫酸与甲磺酸)中的电化学行为,并对该体系在间接有机电合成中的应用进行了探索.结果表明:当硫酸和甲磺酸(MSA)浓度分别为0.8和1.0 mol·L-1时,Ce3+/Ce4+电对具有最佳的电化学活性;在上述配比的混酸介质中,铈盐的溶解度得到了大幅提高,同时电解氧化铈(III)离子的电流效率较高(92.1%),与纯硫酸体系中的电流效率接近(92.8%),明显高于纯甲磺酸体系(78.5%);该混酸介质中Ce4+在氧化茴香醚生成茴香醛这一过程中也表现出很好的氧化能力. 相似文献