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Thomas J Bruno - One of the best experts on this subject based on the ideXlab platform.

  • Volatility of Mixtures of JP-8 with Biomass Derived Hydroprocessed Renewable Jet Fuels by the Composition Explicit Distillation Curve Method
    2015
    Co-Authors: Jean Van Buren, Kathryn Abel, Tara M. Lovestead, Thomas J Bruno
    Abstract:

    In this paper, we apply the composition explicit distillation curve method to mixtures of JP-8 with hydroprocessed aviation fuels made from camelina (a genus within the flowering plant family Brassicaceae), from castor seed (Ricinus communis), and from waste brown grease used with the Fischer–Tropsch process. For the camelina fuel, the departures (with respect to JP-8) in volatility and in Enthalpy of Combustion are significant for mixtures with 25 and 50% (v/v) in JP-8. Mixtures with only 10% camelina fuel (v/v) show relatively minor departures. In all cases, the departures (with respect to JP-8) are to lower temperatures (higher volatility) and lower molar Enthalpy of Combustion. Mixtures of castor based fuel with JP-8 show essentially no departures in volatility or molar Enthalpy of Combustion up to the 40% distillate volume fraction. Subsequent to this distillate volume fraction, departures are very apparent, with mixtures showing lower volatility and higher molar Enthalpy of Combustion with higher volume fractions of castor based HRJ. Mixtures of the brown grease based fuel show departures to lower volatility and to higher molar Enthalpy of Combustion (with respect to JP-8) as the volume fraction of the brown grease SPK increases

  • characterization of dieseline with the advanced distillation curve method hydrocarbon classification and Enthalpy of Combustion
    Energy & Fuels, 2013
    Co-Authors: Jessica L Burger, R V Gough, Thomas J Bruno
    Abstract:

    The use of fuel blends (incorporating fluids such as natural gas or gasoline) for compression ignition engines may aid in efforts to reduce nitrogen oxides (NOx) and particulate matter emission. The consideration and design of such blends is dependent upon the detailed properties of the particular blend. In this work, we measured blends of 10, 20, 30, 50, 70, 80, and 90% (v/v) gasoline in diesel fuel by use of the advanced distillation curve (ADC) method to determine the hydrocarbon classifications in the various volume fractions. This allows us to track the hydrocarbon families throughout the volatility profile and, most importantly, observe changes in the aromatic content of the distillate cuts. In addition, we have used the composition explicit data channel (a unique capability to sample composition throughout the distillation curve) of the ADC to access thermochemical data, and related this to the temperature data grid reported earlier. This was done by calculating a composite Enthalpy of Combustion b...

  • variability of biodiesel fuel and comparison to petroleum derived diesel fuel application of a composition and Enthalpy explicit distillation curve method
    Energy & Fuels, 2008
    Co-Authors: Lisa S Ott, Thomas J Bruno
    Abstract:

    We have recently introduced several important improvements in the measurement of distillation curves for complex fluids. This new method is a significant improvement over current approaches, featuring, for two examples, a composition-explicit data channel for each distillate fraction (for both qualitative and quantitative analysis) and an assessment of the energy content of each distillate fraction. Herein, we compare the distillation curves of four different biodiesel fuel samples to assess possible variations in the distillation curves based on the source of the fuel. Next, we utilize the composition-explicit data channel to characterize distillate cuts of each of the four biodiesel fuels in terms of available energy content. The measure we use for the fluid energy content of each distillate fraction is the composite Enthalpy of Combustion. On a molar basis, the Enthalpy of Combustion of the four biodiesel fuels increased slightly with increasing distillation temperature. The biodiesel fuel sample with ...

  • Enthalpy of Combustion of fuels as a function of distillate cut application of an advanced distillation curve method
    Energy & Fuels, 2006
    Co-Authors: Thomas J Bruno, Beverly L Smith
    Abstract:

    In previous work, several significant improvements in the measurement of distillation curves for complex fluids were introduced. The modifications to the classical measurement provide for (1) temperature and volume measurements of low uncertainty, (2) temperature control based upon fluid behavior with a model predictive temperature controller, and, most important, (3) a composition-explicit data channel in addition to the temperature−volume relationship that usually comprises the measurement. This latter modification was achieved with a new sampling approach that allows precise qualitative as well as quantitative analyses of each fraction, during the measurement of the distillation curve. In this paper, we utilize the composition-explicit information to characterize distillate cuts in terms of available energy content. This is critical information in the study of real fuels. The measure we use for the fluid energy content is the composite Enthalpy of Combustion for each component selected for identificati...

Shengli Gao - One of the best experts on this subject based on the ideXlab platform.

  • 3d high energy density and low sensitivity materials synthesis structure and physicochemical properties of an azide cu ii complex with 3 5 dinitrobenzoic acid
    RSC Advances, 2014
    Co-Authors: Qing Wei, Sanping Chen, Qi Yang, Xiangyu Liu, Gang Xie, Shengli Gao
    Abstract:

    A novel 3D energetic coordination polymer of azide–Cu(II), Cu(3,5-DNBA)(N3), was synthesized and structurally characterized by single crystal X-ray diffraction, where 3,5-DNBA represents 3,5-dinitrobenzoic acid. Structural analysis reveals that the central Cu(II) ion coordinates with two azide anions and three 3,5-dinitrobenzoic acid anions to form a five-coordinated tetragonal pyramid structure. Remarkably, one oxygen atom in the nitro group displays rare coordination to the Cu(II) ions in the complex. The as-prepared compound showed abrupt thermal decomposition at 268 °C, representing explosive performance and superior thermostability based on DSC and TG-DTG analyses. Sensitivity tests revealed that the title complex was insensitive to external stimuli. The kinetic parameters of an exothermic process for the complex were studied by Kissinger's and Ozawa–Doyle's methods. In addition, the constant-volume Combustion energy of the complex was determined using a precise rotating-bomb calorimeter, and the standard molar Enthalpy of Combustion and the standard molar Enthalpy of formation were calculated.

  • determination of Enthalpy change of reaction of formation molar heat capacity and constant volume Combustion energy of the ternary solid complex lu et2dtc 3 phen
    無機化學學報, 2006
    Co-Authors: Sanping Chen, Shengli Gao, Xuwu Yang, G Xie, Qizhen Shi
    Abstract:

    A ternary solid complex Lu(Et2dtc)3(phen) has been obtained from the reaction of hydrated lutetium chloride with sodium diethyldithiocarbamate (NaEt2dtc), and 1,10-phenanthroline (o-phen•H2O) in absolute ethanol. IR spectrum of the complex indicates that Lu(superscript 3+) binds with sulfur atom in the Na (Et2dtc)3 and nitrogen atom in the o-phen. The Enthalpy change of liquid-phase reaction of formation of the complex, △(subscript r)H(superscript Θ subscript m) (1), was determined to be (-32.821±0.147) kJ•mol^(-1) at 298.15 K by an RD-496 Ⅲ type heat conduction microcalormeter. The Enthalpy change of the solid-phase reaction of formation of the complex, △(subscript r)H(superscript Θ subscript m) (s), was calculated to be (104.160±0.168) kJ•mo1^(-1) on the basis of an appropriate thermochemistry cycle. The thermodynamics of liquid-phase reaction of formation of the complex was investigated by changing the temperature of liquid-phase reaction. Fundamental parameters, such as the activation Enthalpy (△H(superscript Θ subscript ≠)), the activation entropy (△S(superscript Θ subscript ≠)), the activation free energy (△G(superscript Θ subscript ≠)), the apparent reaction rate constant (k), the apparent activation energy (E), the pre-exponential constant (A) and the reaction order (n), were obtained by combination the reaction thermodynamic and kinetic equations with the data of thermokinetic experiments. The molar heat capacity of the complex, C(subscript m), was determined to be (82.23±1.47) J•mol^(-1)•K^(-1) by the same microcalormeter. The constant-volume Combustion energy of the complex, △(subscript c)U, was determined as (-17898.228±8.59) kJ•mol^(-1) by an RBC-Ⅱ type rotating-bomb calorimeter at 298.15 K. Its standard Enthalpy of Combustion, △(subscript c)H(superscript Θ subscript m)and standard Enthalpy of formation, △(subscript f)H(superscript Θ subscript m), were calculated to be (-17917.43±8.11) kJ•mol^(-1) and (-859.95±10.12) kJ•mol^(-1), respectively.

  • low temperature heat capacity and standard molar Enthalpy of formation of copper l threonate hydrate cu c4h6o5 0 5h2o s
    Thermochimica Acta, 2006
    Co-Authors: Wei Qing, Zhicheng Tan, Sanping Chen, Shengli Gao, Shi Qizhen
    Abstract:

    Abstract The solid copper l -threonate hydrate, Cu(C4H6O5)·0.5H2O, was synthesized by the reaction of l -threonic acid with copper dihydrocarbonate and characterized by means of chemical and elemental analyses, IR and TG-DTG. Low-temperature heat-capacity of the title compound has been precisely measured with a small sample precise automated adiabatic calorimeter over the temperature range from 77 to 390 K. An obvious process of the dehydration occurred in the temperature range between 353 and 370 K. The peak temperature of the dehydration of the compound has been observed to be 369.304 ± 0.208 K by means of the heat-capacity measurements. The molar Enthalpy, ΔdHm, of the dehydration of the resulting compound was of 16.490 ± 0.063 kJ mol−1. The experimental molar heat capacities of the solid from 77 to 353 K and the solid from 370 to 390 K have been, respectively, fitted to tow polynomial equations with the reduced temperatures by least square method. The constant-volume energy of Combustion of the compound, ΔcUm, has been determined as being −1616.15 ± 0.72 kJ mol−1 by an RBC-II precision rotating-bomb Combustion calorimeter at 298.15 K. The standard molar Enthalpy of formation of the compound, Δ f H m ° , has been calculated to be −1114.76 ± 0.81 kJ mol−1 from the combination of the data of standard molar Enthalpy of Combustion of the compound with other auxiliary thermodynamic quantities.

  • low temperature heat capacity and standard molar Enthalpy of formation of potassium l threonate hydrate k c4h7o5 h2o
    Chinese Journal of Chemistry, 2006
    Co-Authors: Qing Wei, Zhicheng Tan, Sanping Chen, Shengli Gao, Qizhen Shi
    Abstract:

    The solid potassium L-threonate hydrate, K(C4H7O5)·H2O, was synthesized by the reaction of L-threonic acid with aqueous potassium hydrogen carbonate and characterized by means of chemical and elemental analyses, IR and TG-DTG. Low-temperature heat capacity of K(C4H7O5)·H2O has been precisely measured with a small sample precise automated adiabatic calorimeter over the temperature range from 78 to 395 K. An obvious process of the dehydration occurred in the temperature region of 364–382 K. The peak temperature of the dehydration of the compound has been observed to be (380.524±0.093) K by means of the heat capacity measurements. The molar Enthalpy, ΔdHm, and molar entropy, ΔdSm, of the dehydration of K(C4H7O5)·H2O were calculated to be (19.655±0.012) kJ/mol and (51.618±0.051) J/(K·mol) by the analysis of the heat-capacity curve. The experimental molar heat capacities of the solid from 78 to 362 K and from 382 to 395 K have been respectively fitted to two polynomial equations of heat capacities against the reduced temperatures by least square method. The constant-volume energy of Combustion of the compound, ΔcUm, has been determined to be (−1749.71±0.91) kJ·mol−1 by an RBC-II precision rotary-bomb Combustion calorimeter at 298.15 K. The standard molar Enthalpy of formation of the compound, ΔfH⊖m, has been calculated to be (−1292.56±1.06) kJ·mol−1 from the combination of the standard molar Enthalpy of Combustion of the compound with other auxiliary thermodynamic quantities.

  • measurements of Enthalpy change of reaction of formation molar heat capacity and constant volume Combustion energy of solid complex yb et2dtc 3 phen
    Journal of Rare Earths, 2006
    Co-Authors: Weiming Song, Sanping Chen, Gang Xie, Xuan Chang, Shengli Gao
    Abstract:

    Abstract A ternary solid complex Yb(Et2dtc)3(phen) was obtained from the reaction of hydrous ytterbium chloride with sodium diethyldithiocarbamate (NaEt2dtc), and 1, 10-phenanthroline (o-phen·H2O) in absolute ethanol. The bonding characteristics of the complex were characterized by IR. The result shows Yb3+ bands with two sulfur atoms in the Na(Et2dtc)3 and two nitrogen atoms in the o-phen. The Enthalpy change of liquid-phase reaction of formation of the complex ΔrHθm(1), was determined as being (-24.838±0.114) kJ·mol−1 at 298.15 K, by an RD-496 III type heat conduction microcalormeter. The Enthalpy change of the solid-phase reaction of formation of the complex ΔrHθm(s), was calculated as being (108.015±0.479) kJ·mol−1 on the basis of an appropriate thermochemistry cycle. The thermodynamics of liquid-phase reaction of formation of the complex was investigated by changing the temperature during the liquid-phase reaction. Fundamental parameters, the activation Enthalpy, ΔHθ≠, the activation entropy, ΔSθ≠, the activation free energy, ΔGθ≠, the apparent reaction rate constant k, the apparent activation energy E, the pre-exponential constant A, and the reaction order n, were obtained by a combination of the reaction thermodynamic and kinetic equations with the data from the thermokinetic experiments. At the same time, the molar heat capacity of the complex cm, p, was determined to be (86.34±1.74) J·mol−1·K−1 by the same microcalormeter. The constant-volume Combustion energy of the complex, Δc U, was determined to be (− 17954.08±8.11) kJ·mol−1 by an RBC-II type rotating-bomb calorimeter at 298.15 K. Its standard Enthalpy of Combustion, ΔcHθm, and standard Enthalpy of formation, ΔfHθm were calculated to be (-17973.29±8.11) kJ·mol−1 and (-770.36±9.02) kJ·mol−1 respectively.

Quan Shi - One of the best experts on this subject based on the ideXlab platform.

  • low tmperature heat capacities and standard molar Enthalpy of formation of 4 nitrobenzyl alcohol
    Chinese Journal of Chemistry, 2009
    Co-Authors: Qing Fen Meng, Zhicheng Tan, Ya Ping Dong, Xiaohuan Wang, Quan Shi
    Abstract:

    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.

  • low temperature heat capacities and standard molar Enthalpy of formation of l 3 3 4 dihydroxyphenyl alanine c9h11no4
    Journal of Chemical & Engineering Data, 2008
    Co-Authors: Weiwei Yang, Yuxia Kong, Quan Shi, Zhicheng Tan
    Abstract:

    Low-temperature heat capacities of l-3-(3,4-dihydroxyphenyl) alanine (C9H11NO4) were measured by a precision automated adiabatic calorimeter over the temperature range from (78 to 400) K. A polynomial equation of heat capacities as a function of temperature was fitted by the 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 to be ΔcU = −(21183.5 ± 35.0) J·g−1. The standard molar Enthalpy of Combustion of the compound was determined to be ΔcH°m = −(4177.8 ± 6.9) kJ·mol−1, according to the definition of Combustion Enthalpy. Finally, the standard molar Enthalpy of formation of the compound was calculated to be ΔfH°m = −(935.9 ± 7.0) kJ·mol−1 in accordance with Hess law.

  • low temperature heat capacity and standard molar Enthalpy of formation of crystalline 2 pyridinealdoxime c6h6n2o
    The Journal of Chemical Thermodynamics, 2007
    Co-Authors: Quan Shi, Zhicheng Tan, Bo Tong, Zhiheng Zhang, Julan Zeng
    Abstract:

    Abstract The thermodynamic properties of 2-pyridinealdoxime were investigated through the thermogravimetric (TG) analysis and differential scanning calorimetry (DSC). Low-temperature heat capacity Cp,m of 2-pyridinealdoxime (C6H6N2O; CAS 873-69-8) was measured in the temperature range from (80 to 373) K with a high precision automated adiabatic calorimeter. No phase transition or thermal anomaly was observed in this range. The thermodynamic functions [HT − H298.15] and [ST − S298.15] were calculated in the range from (80 to 375) K. The constant-volume energy and standard molar Enthalpy of Combustion have been determined, Δ c U ( C 6 H 6 N 2 O,cr ) = Δ c H m ∘ (C6H6N2O, cr) = − (3297.11 ± 1.53) kJ · mol−1 (based on Δn being zero in reaction of the Combustion), by means of a precision oxygen-bomb Combustion calorimeter at T = (298.15 ± 0.001) K. The standard molar Enthalpy of formation has been derived, Δ f H m ∘ (C6H6N2O, cr) = (78.56 ± 2.43) kJ · mol−1, from the standard molar Enthalpy of Combustion in combination with other auxiliary thermodynamic quantities through a Hess thermochemical cycle.

  • thermal analysis and calorimetric study of 4 dimethylaminopyridine
    Journal of Chemical & Engineering Data, 2007
    Co-Authors: Quan Shi, Zhicheng Tan, Bo Tong, Shaoxu Wang
    Abstract:

    4-dimethylaminopyridine (dmap) is an important catalyst. the thermodynamic properties of dmap were investigated through differential scanning calorimetry, thermogravimetric analysis, adiabatic calorimetry, and Combustion calorimetry. the low-temperature heat capacity (c-p,c- m) was measured in the temperature range from (80 to 402) k with a high-precision automated adiabatic calorimeter. the melting temperature (t-m), the molar Enthalpy (delta h-fus(m)), and the entropy (delta s-fus(m)) of fusion were determined to be ( 387.094 +/- 0.002) k, ( 21.628 +/- 0.144) kj . mol(-1), and (55.873 +/- 0.372) j . k-1 . mol(-1), respectively. the mole fraction purity of the sample used in the adiabatic calorimetric study was determined to be 0.99964 according to the van't hoff equation. the thermodynamic functions [h-t - h-298.15] and [s-t - s-298.15] were derived in the range from (80 to 400) k with temperature interval of 5 k based on the heat capacity measurements. the constant-volume energy and standard molar Enthalpy of Combustion have been determined, delta u-c (c7h10n2, cr) = -(4232.20 +/- 0.60) kj.mol(-1) and delta h-c(m)0 (c7h10n2, cr) = -(4235.92 +/- 0.60) kj.mol(-1), by means of a precision oxygen-bomb Combustion calorimeter at t = (298.15 +/- 0.001) k. the standard molar Enthalpy of formation has been derived, delta h-f(m)0 (c7h10n2, cr) = (52.20 +/- 1.71) kj.mol(-1), from the standard molar Enthalpy of Combustion in combination with other auxiliary thermodynamic quantities through a hess thermochemical cycle.

  • heat capacity and standard molar Enthalpy of formation of crystalline 2 6 dicarboxypyridine c7h5no4
    The Journal of Chemical Thermodynamics, 2006
    Co-Authors: Quan Shi, Zhicheng Tan, Bo Tong, Lixian Sun, Zhiheng Zhang, Tao Zhang
    Abstract:

    Abstract Low-temperature heat capacity Cp,m of 2,6-dicarboxypyridine (C7H5NO4; CAS 499-83-2) was precisely measured in the temperature range from (80 to 378) K with a high precision automated adiabatic calorimeter. No phase transition or thermal anomaly was observed in this range. The thermodynamic functions [HT − H298.15] and [ST − S298.15] were calculated in the range from (80 to 378) K. The standard molar Enthalpy of Combustion and the standard molar Enthalpy of formation of the compound have been determined, Δ c H m ∘ ( C 7 H 5 NO 4 , cr ) = - ( 2741.41 ± 0.49 ) kJ · mol - 1 and Δ f H m ∘ ( C 7 H 5 NO 4 , cr ) = - ( 727.74 ± 1.50 ) kJ · mol - 1 , by means of a precision oxygen-bomb Combustion calorimeter at T = 298.15 K. The thermodynamic properties of the compound were further investigated through differential scanning calorimeter (DSC) and the thermogravimetric (TG) analysis.

Juan Mentado - One of the best experts on this subject based on the ideXlab platform.

  • standard molar Enthalpy of Combustion and formation of enantiomers s 3 5 dinitro n 1 phenylethyl benzamide and r 3 5 dinitro n 1 phenylethyl benzamide
    The Journal of Chemical Thermodynamics, 2013
    Co-Authors: Juan Mentado
    Abstract:

    Abstract Values of the standard (p° = 0.1 MPa) massic energy of Combustion in oxygen, at T = 298.15 K, for (S)-(+)-3,5-Dinitro-N-(1-phenylethyl)benzamide (S+DPB) and (R)-(−)-3,5-Dinitro-N-(1-phenylethyl)benzamide (R−DPB) were measured by using an isoperibolic micro-Combustion calorimeter. The calorimeter was calibrated and tested recently in our laboratory. The massic energies of enantiomers were used to derive the standard molar Enthalpy of formation in condensate phase, of S+DPB, (−26.86 ± 2.89) kJ ⋅ mol−1 and R−DPB (−25.15 ± 2.90) kJ ⋅ mol−1. Polyethene bags were used as an auxiliary material in the Combustion experiments.

  • calibration and testing of an isoperibolic micro Combustion calorimeter developed to measure the Enthalpy of Combustion of organic compounds containing c h o and n
    The Journal of Chemical Thermodynamics, 2013
    Co-Authors: Juan Mentado, Ernan Mendoza
    Abstract:

    Abstract In order to obtain reliable data of the standard Enthalpy of Combustion of compounds containing carbon, hydrogen, oxygen, and nitrogen atoms, an isoperibolic micro-Combustion calorimeter has been developed from a 22 cm3 1109A Parr semi-micro oxygen bomb. The calorimeter was calibrated with standard benzoic acid and the resulting energy equivalent was e(calor) = (1497.39 ± 0.37) J · K−1, which means an uncertainty of 0.027%. Combustion measurements using salicylic acid and 1,2,4-triazole were made in order to verify the accuracy of the device. The values of −Δcu° at T = 298.15 K for the compounds were (21877.2 ± 4.6) J · g−1, and (19217.7 ± 1.9) J · g−1, respectively, in agreement with the literature values.

  • redesigning the rotating bomb Combustion calorimeter
    The Journal of Chemical Thermodynamics, 2006
    Co-Authors: Henoc Flores, Juan Mentado, Patricia Amador, Luis Alfonso Torres, Myriam Campos, Aaron Rojas
    Abstract:

    Abstract In order to obtain reliable data of the standard Enthalpy of Combustion of compounds containing sulfur or halogen atoms, a new calorimetric rotating-bomb system has been set up. Around a platinum lining Parr 1004 C Combustion bomb, an isoperibolic calorimeter has been designed, constructed and tested. The calorimeter was calibrated by using standard benzoic acid and the resulting equivalent in energy was e(calor) = (14321.2 ± 2.4) J · K−1. Combustion measurements using thianthrene were made in order to verify the accuracy of the device, leading to the value of Δ c u ∘ = - ( 33462.9 ± 5.7 ) J · g - 1 , in agreement with the recommended one.

Zhicheng Tan - One of the best experts on this subject based on the ideXlab platform.

  • low temperature heat capacities and standard molar Enthalpy of formation of gramine c11h14n2
    Chinese Journal of Chemistry, 2011
    Co-Authors: Jingtao Chen, Yuxia Kong, Weiwei Yang, Zhicheng Tan
    Abstract:

    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.

  • low tmperature heat capacities and standard molar Enthalpy of formation of 4 nitrobenzyl alcohol
    Chinese Journal of Chemistry, 2009
    Co-Authors: Qing Fen Meng, Zhicheng Tan, Ya Ping Dong, Xiaohuan Wang, Quan Shi
    Abstract:

    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.

  • low temperature heat capacities and standard molar Enthalpy of formation of l 3 3 4 dihydroxyphenyl alanine c9h11no4
    Journal of Chemical & Engineering Data, 2008
    Co-Authors: Weiwei Yang, Yuxia Kong, Quan Shi, Zhicheng Tan
    Abstract:

    Low-temperature heat capacities of l-3-(3,4-dihydroxyphenyl) alanine (C9H11NO4) were measured by a precision automated adiabatic calorimeter over the temperature range from (78 to 400) K. A polynomial equation of heat capacities as a function of temperature was fitted by the 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 to be ΔcU = −(21183.5 ± 35.0) J·g−1. The standard molar Enthalpy of Combustion of the compound was determined to be ΔcH°m = −(4177.8 ± 6.9) kJ·mol−1, according to the definition of Combustion Enthalpy. Finally, the standard molar Enthalpy of formation of the compound was calculated to be ΔfH°m = −(935.9 ± 7.0) kJ·mol−1 in accordance with Hess law.

  • low temperature heat capacity and standard molar Enthalpy of formation of crystalline 2 pyridinealdoxime c6h6n2o
    The Journal of Chemical Thermodynamics, 2007
    Co-Authors: Quan Shi, Zhicheng Tan, Bo Tong, Zhiheng Zhang, Julan Zeng
    Abstract:

    Abstract The thermodynamic properties of 2-pyridinealdoxime were investigated through the thermogravimetric (TG) analysis and differential scanning calorimetry (DSC). Low-temperature heat capacity Cp,m of 2-pyridinealdoxime (C6H6N2O; CAS 873-69-8) was measured in the temperature range from (80 to 373) K with a high precision automated adiabatic calorimeter. No phase transition or thermal anomaly was observed in this range. The thermodynamic functions [HT − H298.15] and [ST − S298.15] were calculated in the range from (80 to 375) K. The constant-volume energy and standard molar Enthalpy of Combustion have been determined, Δ c U ( C 6 H 6 N 2 O,cr ) = Δ c H m ∘ (C6H6N2O, cr) = − (3297.11 ± 1.53) kJ · mol−1 (based on Δn being zero in reaction of the Combustion), by means of a precision oxygen-bomb Combustion calorimeter at T = (298.15 ± 0.001) K. The standard molar Enthalpy of formation has been derived, Δ f H m ∘ (C6H6N2O, cr) = (78.56 ± 2.43) kJ · mol−1, from the standard molar Enthalpy of Combustion in combination with other auxiliary thermodynamic quantities through a Hess thermochemical cycle.

  • thermal analysis and calorimetric study of 4 dimethylaminopyridine
    Journal of Chemical & Engineering Data, 2007
    Co-Authors: Quan Shi, Zhicheng Tan, Bo Tong, Shaoxu Wang
    Abstract:

    4-dimethylaminopyridine (dmap) is an important catalyst. the thermodynamic properties of dmap were investigated through differential scanning calorimetry, thermogravimetric analysis, adiabatic calorimetry, and Combustion calorimetry. the low-temperature heat capacity (c-p,c- m) was measured in the temperature range from (80 to 402) k with a high-precision automated adiabatic calorimeter. the melting temperature (t-m), the molar Enthalpy (delta h-fus(m)), and the entropy (delta s-fus(m)) of fusion were determined to be ( 387.094 +/- 0.002) k, ( 21.628 +/- 0.144) kj . mol(-1), and (55.873 +/- 0.372) j . k-1 . mol(-1), respectively. the mole fraction purity of the sample used in the adiabatic calorimetric study was determined to be 0.99964 according to the van't hoff equation. the thermodynamic functions [h-t - h-298.15] and [s-t - s-298.15] were derived in the range from (80 to 400) k with temperature interval of 5 k based on the heat capacity measurements. the constant-volume energy and standard molar Enthalpy of Combustion have been determined, delta u-c (c7h10n2, cr) = -(4232.20 +/- 0.60) kj.mol(-1) and delta h-c(m)0 (c7h10n2, cr) = -(4235.92 +/- 0.60) kj.mol(-1), by means of a precision oxygen-bomb Combustion calorimeter at t = (298.15 +/- 0.001) k. the standard molar Enthalpy of formation has been derived, delta h-f(m)0 (c7h10n2, cr) = (52.20 +/- 1.71) kj.mol(-1), from the standard molar Enthalpy of Combustion in combination with other auxiliary thermodynamic quantities through a hess thermochemical cycle.