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Zhicheng Tan - One of the best experts on this subject based on the ideXlab platform.
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low temperature heat capacities and standard Molar Enthalpy of formation of gramine c11h14n2
Chinese Journal of Chemistry, 2011Co-Authors: Jingtao Chen, Yuxia Kong, Weiwei Yang, Zhicheng TanAbstract:Low-temperature heat capacities of gramine (c11h14n2) were measured by a precision automated adiabatic calorimeter over the temperature range from 78 to 401 k. a polynomial equation of heat capacities as a function of temperature was fitted by least squares method. based on the fitted polynomial, the smoothed heat capacities and thermodynamic functions of the compound relative to the standard reference temperature 298.15 k were calculated and tabulated at 5 k intervals. the constant-volume energy of combustion of the compound at t=298.15 k was measured by a precision oxygen-bomb combustion calorimeter as delta(c)u=-(35336.7 +/- 13.9) j center dot g-1. the standard Molar Enthalpy of combustion of the compound was determined to be ?chm0=-(6163.2 +/- 2.4) kj center dot mol-1, according to the definition of combustion Enthalpy. finally, the standard Molar Enthalpy of formation of the compound was calculated to be;chm0=-(166.2 +/- 2.8) kj center dot mol-1 in accordance with hess law.
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low temperature heat capacities and standard Molar Enthalpy of formation of dichloro bis 2 aminopyridine zinc ii zncl2 c5h6n2 2 s
International Journal of Thermophysics, 2010Co-Authors: Wenyan Dan, Yuxia Kong, Yanjuan Liu, Zhicheng TanAbstract:Dichloro bis(2-aminopyridine) zinc (II), ZnCl2(C5H6N2)2(s), was synthesized by the method of solvonthermal synthesis in which 2-aminopyridine and zinc chloride were chosen as the reactants. X-ray crystallography, chemical analysis, and elemental analysis were applied to characterize the structure and composition of the complex. Low-temperature heat capacities of the title compound were measured with a precise small-sample automated adiabatic calorimeter over the temperature range from 78 K to 398 K. A polynomial equation of the heat capacities as a function of temperature was fitted by a least-squares method. Smoothed heat capacities and thermodynamic functions of the compound relative to the standard reference temperature (298.15 K) were calculated and tabulated at intervals of 5 K based on the fitted polynomial. A reasonable thermochemical cycle was designed, and the standard Molar enthalpies of dissolution for the reactants and products of the synthesis reaction in a selected solvent were measured by an isoperibol solution-reaction calorimeter. In addition, the Enthalpy change of the reaction was calculated from the data of the above standard Molar enthalpies of dissolution. Finally, the standard Molar Enthalpy of formation of the complex ZnCl2(C5H6N2)2(s) was determined to be −(400.52 ± 1.66) kJ · mol−1 in accordance with Hess’s law.
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low temperature heat capacities and standard Molar Enthalpy of formation of ethylenediammonium tetrachlorocobaltate ii chloride h3nch2ch2nh3 2 cocl4 cl2 s
Journal of Chemical & Engineering Data, 2010Co-Authors: Wenyan Dan, Yuxia Kong, Chunling Xin, Zhicheng TanAbstract:A coordination compound, ethylenediammonium tetrachlorocobaltate(II) chloride (H3NCH2CH2NH3)(2)[CoCl4]Cl-2, was synthesized by the method of liquid phase synthesis, in which ethylenediamine, cobalt chloride hexahydrate, and concentrated hydrochloric acid were chosen as the reactants. X-ray crystallography, chemical analysis, and elemental analysis were applied to characterize the structure and composition of the complex. Low-temperature heat capacities of the complex were measured with a precise automated adiabatic calorimeter over the temperature range from (78 to 370) K. A polynomial equation of the heat capacities as a function of temperature was fitted by a least-squares method. Smoothed heat capacities and thermodynamic functions of the compound relative to the standard reference temperature of 298.15 K were calculated and tabulated at intervals of 5 K based on the fitted polynomial equation. A reasonable thermochemical cycle was designed, and the standard Molar enthalpies of dissolution of the reactants and products of the synthesis reaction in the selected solvent were measured by an isoperibol solution-reaction calorimeter. The Enthalpy change of the reaction was calculated to be Delta H-r(m)o = (17.612 +/- 0.571) kJ.mol(-1) from the data of the standard Molar enthalpies of dissolution. The standard Molar Enthalpy of formation of the title compund was determined to be Delta H-f(m)o {(NH3CH2CH2NH3)(2)[CoCl4]Cl-2, s} = (1499.54 +/- 2.73) kJ.mol(-1) in accordance with Hess's law.
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low tmperature heat capacities and standard Molar Enthalpy of formation of 4 nitrobenzyl alcohol
Chinese Journal of Chemistry, 2009Co-Authors: Qing Fen Meng, Zhicheng Tan, Ya Ping Dong, Xiaohuan Wang, Quan ShiAbstract:Low-temperature heat capacities of 4-nitrobenzyl alcohol (4-NBA) have been measured by a high precision automated adiabatic calorimeter over the temperature range from 78 to 396 K. The melting temperature, the Molar Enthalpy and entropy of the phase transition were determined to be (336.426 +/- 0.088) K, (20.97 +/- 0.13) kJ.mol(-1) and (57.24 +/- 0.36) J.K(-1).mol(-1), respectively. The thermodynamic functions [H(T)-H(298.15 K)] and [S(T)-S(298.15 K)] were calculated in the range from 80 to 400 K at the interval of 5 K. The constant-volume energy and standard Molar Enthalpy of combustion have been determined, Delta(c)U(C(7)H(7)NO(3), s) = - (3549.11 +/- 1.47) kJ.mol(-1) and Delta(c)H(m)(o)(C(7)H(7)NO(3), s) = - (3548.49 +/- 1.47) kJ.mol(-1), by means of a precision oxygen-bomb combustion calorimeter at T=298.15 K. The standard Molar Enthalpy of formation has been derived, Delta(f)H(m)(o)(C(7)H(7)NO(3), s) = - (206.49 +/- 2.52) kJ.mol(-1), from the standard Molar Enthalpy of combustion in combination with other auxiliary thermodynamic quantities through a Hess thermochemical cycle.
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low temperature heat capacities and standard Molar Enthalpy of formation of sodium benzoate c6h5coona s
Thermochimica Acta, 2009Co-Authors: Yuxia Kong, Weiwei Yang, Zhicheng TanAbstract:Abstract Sodium benzoate was synthesized by the method of liquid phase synthesis, in which benzoic acid and anhydrous sodium carbonate were chosen as the reactants. The structure and composition of the compound were characterized by FTIR, chemical analysis, elemental analysis and X-ray powder diffraction techniques. Low temperature heat capacities of the compound were measured by a precision automated adiabatic calorimeter over the temperature range from 78 to 400 K. A polynomial equation of the heat capacities as a function of the temperature was fitted by least square method. The smoothed heat capacities and the thermodynamic functions of the compound relative to 298.15 K have been calculated based on the equation. In accordance with Hess law, the standard Molar Enthalpy of formation of the title compound C6H5COONa (s) was determined to be Δ f H ° m [ C 6 H 5 COONa , s ] = − ( 642.56 ± 0.64 ) kJ mo l − 1 by using an isoperibol solution-reaction calorimeter.
P A G Ohare - One of the best experts on this subject based on the ideXlab platform.
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a fluorine bomb calorimetric determination of the standard Molar Enthalpy of formation of silicon disulfide sis2 cr at the temperature 298 15 k enthalpies of dissociation of si s bonds
The Journal of Chemical Thermodynamics, 1997Co-Authors: Iwona Tomaszkiewicz, G A Hope, P A G OhareAbstract:Abstract A synthesis of high-purity silicon disulfide SiS 2 is described, and the F.t.-Raman spectrum of the solid is reported for the first time. The standard massic energy of reaction of SiS 2 (cr) with fluorine was measured in a bomb calorimeter. The combustion reaction was shown to proceed as follows: SiS 2 (cr)+8F 2 (g)=SiF 4 (g)+2SF 6 (g). The derived standard Molar Enthalpy of formation is: Δ f H m o (SiS 2 , cr, 298.15 K)=−(254.6±2.9) kJ·mol −1 . This value differs significantly from those determined by solution-reaction calorimetry, but is in fair agreement with results obtained by means of third-law treatments of high-temperature equilibria. The ratio of Molar enthalpies of dissociation of the “first” and “second” bonds in SiS 2 (g), κ= D m o (S–SiS)/ D m o (SiS)=(0.57±0.03), is similar to κs reported previously for SiO 2 and SiSe 2 .
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thermodynamic properties of silicides vi pentamolybdenum trisilicide mo5si3 fluorine combustion calorimetric determination of the standard Molar Enthalpy of formation at the temperature 298 15 k
The Journal of Chemical Thermodynamics, 1997Co-Authors: Iwona Tomaszkiewicz, G A Hope, Charles M Beck, P A G OhareAbstract:Abstract The standard Molar Enthalpy of formation ΔfHmoof pentamolybdenum trisilicide Mo5Si3has been determined by fluorine combustion calorimetry to be −(314.3 ± 8.3) kJ·mol−1atT= 298.15 K andpo= 101.325 kPa. Conventional thermodynamic properties of Mo5Si3are tabulated toT= 2100 K. Thermodynamic quantities to the same temperature maximum are also given for the high-temperature oxidation reactions: 2MoSi2(s) + 702(g) = 2MoO3(s) + 4SiO2(s), and 5MoSi2(s) + 702(g) = Mo5Si3(s) + 7SiO2(s) on the basis of the most up-to-date thermodynamic values.
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thermodynamic properties of silicides v fluorine combustion calorimetric determination of the standard Molar Enthalpy of formation at the temperature 298 15 k of trimolybdenum monosilicide mo3si and a critical assessment of its thermodynamic properti
The Journal of Chemical Thermodynamics, 1996Co-Authors: Iwona Tomaszkiewicz, G A Hope, Charles M Beck, P A G OhareAbstract:The massic (formerly called specific) energies of combustion in fluorine of two different specimens of trimolybdenum monosilicide have been measured in a bomb calorimeter and the standard Molar Enthalpy of formation ΔfHmo(Mo3Si, cr, 298.15 K) determined to be −(125.2 ± 5.8) kJ ·mol−1. A critical evaluation of the thermodynamic properties of Mo3Si is also presented, and recommended values for the standard Molar Enthalpy increments, standard Molar heat capacities, standard Molar enthalpies of formation, and standard Molar Gibbs free energies of formation have been tabulated toT= 2300 K.
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fluorine combustion calorimetric determinations of the standard Molar Enthalpy changes for the formation of sise2 cr sise1 94 cr and sise1 94 vit and for the transition sise1 94 vit sise1 94 cr at the temperature t 298 15 k implications of the result
The Journal of Chemical Thermodynamics, 1994Co-Authors: Iwona Tomaszkiewicz, S Susman, K J Volin, P A G OhareAbstract:Abstract Fluorine-bomb calorimetry was used to determine the standard massic energies of combustion Δcuo of the silicon selenides SiSe2(cr), SiSe1.94(cr), and SiSe1.94(vit), according to the combustion reaction: SiSev(s) + (2 + 3v)F2(g) = SiF4(g) + vSeF6(g). The following additional results were derived for the standard Molar energy of combustion ΔcUom; the standard Molar Enthalpy of combustion ΔcHom; and the standard Molar Enthalpy of formation ΔfHom, all at the temperature T = 298.15 K and for the standard pressure po = 101.325 kPa See Table. Standard thermodynamic properties of the gas SiSe(g) were calculated by means of the conventional formulae of statistical mechanics. On the basis of the thermochemical quantities given above, the standard Molar Enthalpy of the transition: SiSe1.94(vit) = SiSe1.94(cr) is ΔtrsHom = -(6.5 ± 2.2) kJ·mol-1 at T = 291.15 K. (All uncertainties in this abstract correspond to twice the standard deviation of the mean.) Implications of the thermochemical quantities for the enthalpies of dissociation Dom (SiX) and Dom (X-SiX), where X denotes O, S, or Te.
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thermodynamic properties of silicides iii specific energy of combustion in fluorine of a hyperstoichiometric molybdenum disilicide the standard Molar Enthalpy of formation δfhom of mosi2 067 0 002 at the temperature 298 15 k
The Journal of Chemical Thermodynamics, 1993Co-Authors: P A G OhareAbstract:Abstract Calorimetric measurements of the specific energy of combustion in fluorine of a thoroughly analyzed sample of MoSi 2.067±0.002 according to the reaction: MoSi 2.067 (cr)+7.134F 2 (g) = MoF 6 (g)+2.067SiF 4 (g), gave the result Δ c u o = -(30824±7) J·g -1 . The derived standard Molar Enthalpy of formation Δ f H o m (MoSi 2.067 ) at T = 298.15 K and p o = 101.325 kPa is -(140.5±4.2) kJ·mol -1 , and from it Δ f H o m (MoSi 2 , 298.15 K) and the standard Molar Gibbs free energy of formation Δ f G o m (MoSi 2 , 298.15 K) are estimated to be -(137.1±4.5) kJ·mol -1 and -(136.2±4.5) kJ·mol -1 , respectively. Those quantities are compared with the values for Δ f H o m and Δ f G o m of MoSi 2 determined in previous investigations.
Iwona Tomaszkiewicz - One of the best experts on this subject based on the ideXlab platform.
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a fluorine bomb calorimetric determination of the standard Molar Enthalpy of formation of silicon disulfide sis2 cr at the temperature 298 15 k enthalpies of dissociation of si s bonds
The Journal of Chemical Thermodynamics, 1997Co-Authors: Iwona Tomaszkiewicz, G A Hope, P A G OhareAbstract:Abstract A synthesis of high-purity silicon disulfide SiS 2 is described, and the F.t.-Raman spectrum of the solid is reported for the first time. The standard massic energy of reaction of SiS 2 (cr) with fluorine was measured in a bomb calorimeter. The combustion reaction was shown to proceed as follows: SiS 2 (cr)+8F 2 (g)=SiF 4 (g)+2SF 6 (g). The derived standard Molar Enthalpy of formation is: Δ f H m o (SiS 2 , cr, 298.15 K)=−(254.6±2.9) kJ·mol −1 . This value differs significantly from those determined by solution-reaction calorimetry, but is in fair agreement with results obtained by means of third-law treatments of high-temperature equilibria. The ratio of Molar enthalpies of dissociation of the “first” and “second” bonds in SiS 2 (g), κ= D m o (S–SiS)/ D m o (SiS)=(0.57±0.03), is similar to κs reported previously for SiO 2 and SiSe 2 .
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thermodynamic properties of silicides vi pentamolybdenum trisilicide mo5si3 fluorine combustion calorimetric determination of the standard Molar Enthalpy of formation at the temperature 298 15 k
The Journal of Chemical Thermodynamics, 1997Co-Authors: Iwona Tomaszkiewicz, G A Hope, Charles M Beck, P A G OhareAbstract:Abstract The standard Molar Enthalpy of formation ΔfHmoof pentamolybdenum trisilicide Mo5Si3has been determined by fluorine combustion calorimetry to be −(314.3 ± 8.3) kJ·mol−1atT= 298.15 K andpo= 101.325 kPa. Conventional thermodynamic properties of Mo5Si3are tabulated toT= 2100 K. Thermodynamic quantities to the same temperature maximum are also given for the high-temperature oxidation reactions: 2MoSi2(s) + 702(g) = 2MoO3(s) + 4SiO2(s), and 5MoSi2(s) + 702(g) = Mo5Si3(s) + 7SiO2(s) on the basis of the most up-to-date thermodynamic values.
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thermodynamic properties of silicides v fluorine combustion calorimetric determination of the standard Molar Enthalpy of formation at the temperature 298 15 k of trimolybdenum monosilicide mo3si and a critical assessment of its thermodynamic properti
The Journal of Chemical Thermodynamics, 1996Co-Authors: Iwona Tomaszkiewicz, G A Hope, Charles M Beck, P A G OhareAbstract:The massic (formerly called specific) energies of combustion in fluorine of two different specimens of trimolybdenum monosilicide have been measured in a bomb calorimeter and the standard Molar Enthalpy of formation ΔfHmo(Mo3Si, cr, 298.15 K) determined to be −(125.2 ± 5.8) kJ ·mol−1. A critical evaluation of the thermodynamic properties of Mo3Si is also presented, and recommended values for the standard Molar Enthalpy increments, standard Molar heat capacities, standard Molar enthalpies of formation, and standard Molar Gibbs free energies of formation have been tabulated toT= 2300 K.
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fluorine combustion calorimetric determinations of the standard Molar Enthalpy changes for the formation of sise2 cr sise1 94 cr and sise1 94 vit and for the transition sise1 94 vit sise1 94 cr at the temperature t 298 15 k implications of the result
The Journal of Chemical Thermodynamics, 1994Co-Authors: Iwona Tomaszkiewicz, S Susman, K J Volin, P A G OhareAbstract:Abstract Fluorine-bomb calorimetry was used to determine the standard massic energies of combustion Δcuo of the silicon selenides SiSe2(cr), SiSe1.94(cr), and SiSe1.94(vit), according to the combustion reaction: SiSev(s) + (2 + 3v)F2(g) = SiF4(g) + vSeF6(g). The following additional results were derived for the standard Molar energy of combustion ΔcUom; the standard Molar Enthalpy of combustion ΔcHom; and the standard Molar Enthalpy of formation ΔfHom, all at the temperature T = 298.15 K and for the standard pressure po = 101.325 kPa See Table. Standard thermodynamic properties of the gas SiSe(g) were calculated by means of the conventional formulae of statistical mechanics. On the basis of the thermochemical quantities given above, the standard Molar Enthalpy of the transition: SiSe1.94(vit) = SiSe1.94(cr) is ΔtrsHom = -(6.5 ± 2.2) kJ·mol-1 at T = 291.15 K. (All uncertainties in this abstract correspond to twice the standard deviation of the mean.) Implications of the thermochemical quantities for the enthalpies of dissociation Dom (SiX) and Dom (X-SiX), where X denotes O, S, or Te.
A Z Francesconi - One of the best experts on this subject based on the ideXlab platform.
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application of the prigogine flory patterson model to excess Molar Enthalpy of binary liquid mixtures of 1 nonanol or 1 decanol with acetonitrile at atmospheric pressure and 298 15 303 15 and 308 15 k
Journal of Molecular Liquids, 2014Co-Authors: Dimas Henrique Lanfredi Viola, A Z FrancesconiAbstract:Abstract Excess Molar Enthalpy data of 1-nonanol + acetonitrile and 1-decanol + acetonitrile mixtures as a function of composition at atmospheric pressure at 298.15, 303.15 and 308.15 K have been used to test the applicability of the Prigogine–Flory–Patterson (PFP) model. Both systems exhibit positive excess Molar Enthalpy values over the whole composition range for the studied temperature range. The model has only one adjustable parameter and correlates the data within a standard deviation up to 309 J mol− 1. The interactional contribution of the model is the most important one to describe the experimental values.
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measurements of excess Molar Enthalpy and excess Molar heat capacity of 1 heptanol or 1 octanol diethylamine or s butylamine mixtures at 298 15 k and 0 1 mpa
Journal of Thermal Analysis and Calorimetry, 2009Co-Authors: Ricardo Figueiredo Checoni, A Z FrancesconiAbstract:Abstract Experimental data of excess Molar Enthalpy (H mE) and excess Molar heat capacity (C pmE) of binary mixtures containing (1-heptanol or 1-octanol)+(diethylamine or s-butylamine) have been determined as a function of composition at 298.15 K and at 0.1 MPa using a modified 1455 Parr solution calorimeter. The excess Molar Enthalpy data are negative and show parabolic format over the whole composition range; however, the excess Molar heat capacity values, whose curves show a S-shape, are positive in the 0.0 to 0.7 Molar fraction range and negative between the Molar fraction values 0.7 to 1.0. The applicability of the ERAS-model to correlate the excess Molar Enthalpy data was tested. The calculated data values are in good agreement with the experimental ones. The experimental behavior of H mE is interpreted in terms of specific interactions between 1-alkanol and amine molecules.
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experimental study and eras modeling of the excess Molar Enthalpy of acetonitrile 1 heptanol or 1 octanol mixtures at 298 15 313 15 and 323 15 k and atmospheric pressure
The Journal of Chemical Thermodynamics, 2008Co-Authors: Ricardo Figueiredo Checoni, Luciane Dagostini, A Z FrancesconiAbstract:Abstract As a continuation of our studies on excess functions of binary systems, experimental data of excess Molar Enthalpy ( H m E ) of (acetonitrile + 1-heptanol or 1-octanol) mixtures have been determined as a function of composition at (298.15, 313.15, and 323.15) K at atmospheric pressure using a modified 1455 PARR mixture calorimeter. The H m E is positive for both systems over the whole composition range. The applicability of the ERAS-Model to correlate H m E of the mixtures studied was tested. The agreement between experimental and calculated values is satisfactory.
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application of the prigogine flory patterson model to excess Molar Enthalpy of binary liquid mixtures containing acetonitrile and 1 alkanol
Journal of Molecular Liquids, 2008Co-Authors: A C Galvao, A Z FrancesconiAbstract:Abstract Excess Molar Enthalpy of acetonitrile + 1-pentanol and acetonitrile + 1-hexanol as a function of composition at 288.15, 293.15, 298.15 and 303.15 K under atmospheric pressure were used to test the applicability of the Prigogine–Flory–Patterson (PFP) model. The model, with only one adjustable parameter, shows to be able to correlate the experimental data of the investigated mixtures within a standard deviation up to 163 Jmol − 1 . The interactional contribution of the model plays the main role to describe the excess Molar Enthalpy and its ability of multiproperty description is not observed for the studied systems.
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partial Molar Enthalpy properties and correlation of excess Molar Enthalpy data of acetonitrile diethylamine or s butylamine mixtures at various temperatures and atmospheric pressure
Thermochimica Acta, 2006Co-Authors: Ricardo Figueiredo Checoni, A Z FrancesconiAbstract:Abstract Experimental data of excess Molar Enthalpy ( H m E ) of binary mixtures of acetonitrile + diethylamine or S -butylamine mixtures as a function of composition at 288.15, 293.15, 298.15 and 303.15 K at atmospheric pressure have been used to calculate excess partial Molar Enthalpy and partial Molar Enthalpy of each component as a function of composition as well as partial Molar Enthalpy properties at infinite dilution. The Flory and Prigogine–Flory–Patterson (PFP) theories were applied to correlate the H m E data. The results of the calculations as well as the influence of temperature and isomers chain on the partial Molar Enthalpy properties are discussed.
Weiwei Yang - One of the best experts on this subject based on the ideXlab platform.
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low temperature heat capacities and standard Molar Enthalpy of formation of gramine c11h14n2
Chinese Journal of Chemistry, 2011Co-Authors: Jingtao Chen, Yuxia Kong, Weiwei Yang, Zhicheng TanAbstract:Low-temperature heat capacities of gramine (c11h14n2) were measured by a precision automated adiabatic calorimeter over the temperature range from 78 to 401 k. a polynomial equation of heat capacities as a function of temperature was fitted by least squares method. based on the fitted polynomial, the smoothed heat capacities and thermodynamic functions of the compound relative to the standard reference temperature 298.15 k were calculated and tabulated at 5 k intervals. the constant-volume energy of combustion of the compound at t=298.15 k was measured by a precision oxygen-bomb combustion calorimeter as delta(c)u=-(35336.7 +/- 13.9) j center dot g-1. the standard Molar Enthalpy of combustion of the compound was determined to be ?chm0=-(6163.2 +/- 2.4) kj center dot mol-1, according to the definition of combustion Enthalpy. finally, the standard Molar Enthalpy of formation of the compound was calculated to be;chm0=-(166.2 +/- 2.8) kj center dot mol-1 in accordance with hess law.
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thermochemistry on dodecylamine hydrochloride and bis dodecylammonium tetrachlorozincate
Journal of Thermal Analysis and Calorimetry, 2011Co-Authors: Y Y Di, Donghua He, Yuxia Kong, Weiwei YangAbstract:Dodecylamine hydrochloride C12H25NH3·Cl(s) and bis-dodecylammonium tetrachlorozincate (C12H25NH3)2ZnCl4(s) were synthesized by the method of liquid phase reaction. The constant-volume energy of combustion of dodecylamine hydrochloride was measured by means of a RBC-II precision rotating-bomb combustion calorimeter at T = (298.15 ± 0.001) K. The standard Molar Enthalpy of formation of C12H25NH3·Cl(s) was calculated to be $$ \Updelta_{\rm{f}} H_{\rm{m}}^{\rm{o}} $$ (C12H25NH3·Cl, s) = −(706.79 ± 3.97) kJ mol−1 from the constant-volume energy of combustion. In accordance with Hess’ law, a reasonable thermochemical cycle was designed and the Enthalpy change of the synthesis reaction of the complex (C12H25NH3)2ZnCl4(s) was determined by use of an isoperibol solution-reaction calorimeter. The standard Molar Enthalpy of formation of (C12H25NH3)2ZnCl4(s) was calculated as $$ \Updelta_{\rm{f}} H_{\rm{m}}^{\rm{o}} $$ [(C12H25NH3)2ZnCl4, s] = −(1862.14 ± 7.95) kJ mol−1 from the standard Molar Enthalpy of formation of C12H25NH3·Cl(s) and other auxiliary thermodynamic data.
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synthesis crystal structure and standard Molar Enthalpy of formation of bis trans bis n n dimethyl 1 r phenyl 2 s methyl 2 aminoethoxy n o copper ii heptahydrate
The Journal of Chemical Thermodynamics, 2011Co-Authors: Wenyan Dan, Yuxia Kong, Weiwei Yang, Jingtao Chen, Qiang Wang, Daqi WangAbstract:Abstract A novel complex, bis(trans-bis(N,N-dimethyl-(1-(R)-phenyl-2-(S)-methyl-2-aminoethoxy-N,O))-copper(II)) heptahydrate (abbreviated as Cu2(C11H16NO)4·7H2O(cr)), was synthesized by the method of liquid phase reflux. The composition and structure of the complex were characterized by chemical analysis, elemental analysis, FTIR, and X-ray crystallography. A reasonable thermochemical cycle was designed based on the preparation reaction of the coordination compound, and standard Molar enthalpies of dissolution of reactants and products were measured by an isoperibol solution-reaction calorimeter. Finally, the standard Molar Enthalpy of formation of the complex Cu2(C11H16NO)4·7H2O(cr) was determined to be −(4525.22 ± 13.71) kJ · mol−1 in accordance with Hess’s law.
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low temperature heat capacities and standard Molar Enthalpy of formation of sodium benzoate c6h5coona s
Thermochimica Acta, 2009Co-Authors: Yuxia Kong, Weiwei Yang, Zhicheng TanAbstract:Abstract Sodium benzoate was synthesized by the method of liquid phase synthesis, in which benzoic acid and anhydrous sodium carbonate were chosen as the reactants. The structure and composition of the compound were characterized by FTIR, chemical analysis, elemental analysis and X-ray powder diffraction techniques. Low temperature heat capacities of the compound were measured by a precision automated adiabatic calorimeter over the temperature range from 78 to 400 K. A polynomial equation of the heat capacities as a function of the temperature was fitted by least square method. The smoothed heat capacities and the thermodynamic functions of the compound relative to 298.15 K have been calculated based on the equation. In accordance with Hess law, the standard Molar Enthalpy of formation of the title compound C6H5COONa (s) was determined to be Δ f H ° m [ C 6 H 5 COONa , s ] = − ( 642.56 ± 0.64 ) kJ mo l − 1 by using an isoperibol solution-reaction calorimeter.
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low temperature heat capacities and standard Molar Enthalpy of formation of potassium benzoate c7h5o2k s
International Journal of Thermophysics, 2009Co-Authors: Weiwei Yang, Yuxia Kong, Zhenfen Yin, Zhicheng TanAbstract:Potassium benzoate C7H5O2K (CAS Registry No. 582-25-2) was synthesized by the method of liquid phase reaction. Chemical and elemental analyses, FTIR, and X-ray powder diffraction (XRD) techniques were applied to characterize the composition and structure of the compound. Low-temperature heat capacities of the compound were measured by a precision automated adiabatic calorimeter over the temperature range from 78 K to 398 K. A polynomial equation of the heat capacities as a function of temperature was fitted by the least-squares method. Smoothed heat capacities and thermodynamic functions of the compound were calculated based on the fitted polynomial. In accordance with Hess’s law, a reasonable thermochemical cycle was designed, and 100 mL of 1 mol · dm−3 NaOH solution was chosen as the calorimetric solvent. The standard Molar enthalpies of dissolution for the reactants and products of the supposed reaction in the selected solvent were measured by an isoperibol solution-reaction calorimeter. Finally, the standard Molar Enthalpy of formation of the title compound C7H5O2K (s) was derived to be -(610.94 ± 0.77) kJ · mol−1.