Based on the Hückel determinant of conjugated chain polyene,an ordinary formula of reduced order is infered directly only by the use of determinant algebra.Two half-reduced order formulae are deduced thereby.As a...Based on the Hückel determinant of conjugated chain polyene,an ordinary formula of reduced order is infered directly only by the use of determinant algebra.Two half-reduced order formulae are deduced thereby.As a result,the relationship of Hückel determinant between the conjugated ring polyene and conjugated chain polyene is clarified.Examples are offered also.展开更多
Focusing on the most important NaAl(OH)4-NaOH-H2O system in the industry of alumina production, the feasibility of establishing a calculation model of activity coefficients according to Debye-Hückel theory via th...Focusing on the most important NaAl(OH)4-NaOH-H2O system in the industry of alumina production, the feasibility of establishing a calculation model of activity coefficients according to Debye-Hückel theory via the equilibrium solubility data of sodium aluminate solution is discussed in this paper. Firstly, the hypotheses for applying Debye-Hückel theory into NaAl(OH)4-NaOH-H2O system are involved and the values of parameters are determined. Then the applicability of Debye-Hückel model in NaAl(OH)4-NaOH-H2O system is testified. The results indicate that Debye-Hückel model is applicable to the establishment of calculation model of activity coefficients in NaAl(OH)4-NaOH-H2O system and the value of -NaAl(OH)4 is estimated as 0.3595 nm.展开更多
Peter Debye and Erich Hückel had developed a theory for the ionic activity coefficients in dilute solutions of strong electrolytes some 95 years ago [1]. Their limiting law still stands and is confirmed as close ...Peter Debye and Erich Hückel had developed a theory for the ionic activity coefficients in dilute solutions of strong electrolytes some 95 years ago [1]. Their limiting law still stands and is confirmed as close to reality in many experiments. In a previous article [2], it is shown that these limiting activity coefficients arise because the electrical contribution in the electrochemical potential of ionic species is overestimated traditionally with a factor 2. The smaller value removes inconsistencies in the models and complies better with the basic electrostatic principles. In this article further evidence is given in support of this alternative description. As consequence the dilute activity coefficients become unity, e.g. are removed, which means that the electrochemical potential of ions in dilute solutions is expressed directly in concentration, instead of activity, which simplifies modelling in such dilute solutions.展开更多
Complexation of two ligands, iminodiacetic acid and ethylenediamine-N,N′-diacetic acid, with molybdenum（Ⅵ） was studied in aqueous solutions. Molybdenum（Ⅵ） forms a mononuclear complex with the aforementioned lig...Complexation of two ligands, iminodiacetic acid and ethylenediamine-N,N′-diacetic acid, with molybdenum（Ⅵ） was studied in aqueous solutions. Molybdenum（Ⅵ） forms a mononuclear complex with the aforementioned ligands of the type MoO3L^2-. All measurements have been carried out at 25 ℃ and different ionic strengths ranging from 0.1 to 1.0 mol·L^-1 of NaClO4, with the pH justified to 6.0. Equilibrium concentration products and stoichiometry of the complexes have been determined from a combination of potentiometric and UV spectroscopic measurements. Comparison of the ionic strength effect on these complex formation reactions has been made using a Debye-Hückel type equation and Bronsted-Guggenheim-Scatchard specific ion interaction theory （SIT）. Debye-Hückel theory predicted the first order effects on simple electrolyte solutions. Interactions between the reacting species and the ionic medium were taken into account in the SIT model. All of the calculations have been done by the computer program Excel 2000.展开更多
基金The National Basic Research Program of China(973Program)(No.2009CB623203)the National Natural Science Foundation of China(No.51078186)+2 种基金Program for Special Talents in Six Fields of Jiangsu Province(No.2008169)the Natural Science Foundation of Jiangsu Province(No.BK2010071)China Postdoctoral Science Foundation(No.200902500)
基金Supported by the National Natural Science Foundation of China(No.51422212 and 21307142)Ningbo Science and Technology Bureau(No.2015A610248,2015B11003)+2 种基金Zhejiang Provincial Natural Science Foundation of China(LR16B030001)C.Wong Education Foundation(rczx0800)Chinese Academy of Science(QYZDB-SSW-JSC037,ZDRW-CN-2016-1)
文摘Based on the Hückel determinant of conjugated chain polyene,an ordinary formula of reduced order is infered directly only by the use of determinant algebra.Two half-reduced order formulae are deduced thereby.As a result,the relationship of Hückel determinant between the conjugated ring polyene and conjugated chain polyene is clarified.Examples are offered also.
文摘Focusing on the most important NaAl(OH)4-NaOH-H2O system in the industry of alumina production, the feasibility of establishing a calculation model of activity coefficients according to Debye-Hückel theory via the equilibrium solubility data of sodium aluminate solution is discussed in this paper. Firstly, the hypotheses for applying Debye-Hückel theory into NaAl(OH)4-NaOH-H2O system are involved and the values of parameters are determined. Then the applicability of Debye-Hückel model in NaAl(OH)4-NaOH-H2O system is testified. The results indicate that Debye-Hückel model is applicable to the establishment of calculation model of activity coefficients in NaAl(OH)4-NaOH-H2O system and the value of -NaAl(OH)4 is estimated as 0.3595 nm.
文摘Peter Debye and Erich Hückel had developed a theory for the ionic activity coefficients in dilute solutions of strong electrolytes some 95 years ago [1]. Their limiting law still stands and is confirmed as close to reality in many experiments. In a previous article [2], it is shown that these limiting activity coefficients arise because the electrical contribution in the electrochemical potential of ionic species is overestimated traditionally with a factor 2. The smaller value removes inconsistencies in the models and complies better with the basic electrostatic principles. In this article further evidence is given in support of this alternative description. As consequence the dilute activity coefficients become unity, e.g. are removed, which means that the electrochemical potential of ions in dilute solutions is expressed directly in concentration, instead of activity, which simplifies modelling in such dilute solutions.
文摘Complexation of two ligands, iminodiacetic acid and ethylenediamine-N,N′-diacetic acid, with molybdenum（Ⅵ） was studied in aqueous solutions. Molybdenum（Ⅵ） forms a mononuclear complex with the aforementioned ligands of the type MoO3L^2-. All measurements have been carried out at 25 ℃ and different ionic strengths ranging from 0.1 to 1.0 mol·L^-1 of NaClO4, with the pH justified to 6.0. Equilibrium concentration products and stoichiometry of the complexes have been determined from a combination of potentiometric and UV spectroscopic measurements. Comparison of the ionic strength effect on these complex formation reactions has been made using a Debye-Hückel type equation and Bronsted-Guggenheim-Scatchard specific ion interaction theory （SIT）. Debye-Hückel theory predicted the first order effects on simple electrolyte solutions. Interactions between the reacting species and the ionic medium were taken into account in the SIT model. All of the calculations have been done by the computer program Excel 2000.
