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The heat capacity of diethyl acetamidomalonate (DEAM) has been studied using an adiabatic calorimeter in the temperature range from (78 to 395) K. No thermal anomalies were observed in temperature regions from (78 to 344) K and from (375 to 395) K, where the heat capacity data were fit to two polynomial equations. A solid–liquid phase transition was detected in temperatures from (344 to 375) K. The phase transition temperature, enthalpy, entropy and mole fraction purity of this compound were determined to be 368.72 K, 34.3 kJ·mol–1, 93.0 J·K–1·mol–1 and 0.9997(mole fraction), respectively, based on the experimental data in the phase transition region. The thermodynamic functions of DEAM relative to the reference temperature of 298.15 K were derived based on the fitted heat capacity data in the entire experimental region.

Air- and water-stable hydrophobic ionic liquids N-alkylpyridinium bis(trifluoromethylsulfonyl)imide ([Cnpy][NTf2], n = 3, 6) were synthesized. The density, surface tension, dynamic viscosity, and electrical conductivity of [C6py][NTf2] were measured in the range of T = (283.15 to 338.15) K. The density, dynamic viscosity, and electrical conductivity of [C3py][NTf2] were measured in the range of T = (308.15 to 338.15) K. The melting and glass transition temperatures of the two ILs were determined according to the differential scanning calorimetry (DSC). The physicochemical properties, including molecular volume, standard molar entropy, lattice energy, parachor, molar enthalpy of vaporization, interstice volume, interstice fraction, and thermal expansion coefficient, were estimated in terms of empirical and semiempirical equations, as well as the interstice model theory on the base of the experimental values. The dynamic viscosity and electrical conductivity values were fitted by Vogel–Fulcher–Tammann (VFT)...

A complex of lutetium hydrochloric acid coordinated with 2-aminoacetic acid (C2H5O2N), Lu(C2H5O2N)2Cl3·3H2O, was synthesized. The molar heat capacities (Cp,m) and thermodynamic properties of the co...

An n-butanol-based nanofluid containing nanowire-shaped β-FeOOH was synthesized by a solvothermal method. The nanofluid was stable for 7 days without any precipitation with 3.0 mM SDBS as stabilizer. Uniform β-FeOOH nanowires with high aspect ratios were fabricated. The heat capacities of the obtained β-FeOOH sample, the base fluid, and the nanofluid were determined by an adiabatic calorimeter. Smoothed heat capacities and thermodynamic functions of the obtained samples, such as H(T/K) − H(298.15 K) and S(T/K) − S(298.15 K), were calculated based on the fitted polynomials and the relationships of the thermodynamic functions. These results are very useful to apply to the as-produced nanowire-shaped β-FeOOH and the nanofluid in engineering fields.

Two sulfonate-containing zwitterions, 1-methylimidazolium-3-propylsulfonate zwitterion (MimC(3)SO(3), C(7)H(12)N(2)O(3)S; CAS 179863-07-1) and 1-methylimidazolium-3-butylsulfonate zwitterion (MimC(4)SO(3); C(8)N(14)O(3)S; CAS 148019-49-2), were prepared, and the structures were characterized by (1)H NMR and (13)C NMR and ESI-MS. The thermodynamic properties are investigated through adiabatic caloremetry (AC). differential scanning calorimetry (DSC). and thermogravimetric (TG) analysis. The low-temperature heat capacity (C(p,m)) of MimC(3)SO(3) and MimC(4)SO(3) was measured in the temperature range from (78 to 400) K with a high precision automated calorimeter. The thermodynamic functions [H(T) - H(298.15)] and [S(T) - S(298.15)] were calculated based on the heal capacity data in the range from (80 to 400) K with an interval of 5 K.

The heat capacities of N-benzyloxycarbonyl-L-3-phenylahmine were measured by means of a fully automated adiabatic calorimeter over the temperature range from (79 to 395) K. A solid liquid phase transition corresponding to the melting process was observed. The temperature, the molar enthalpy, and entropy of the phase transition were determined to be 358.799 K. 31.787 kJ.mol(-1), and 88.594 J.K-1.mol(-1), respectively. The mole fraction purity or the sample used in the adiabatic calorimetric study was determined to be 0.9830 according to the Van't Hoff equation. Two equations of temperature dependence for heat capacities in the solid and liquid state are presented. The thermodynamic functions. (H-T - H-298.15K) and (S-T - S-298.15K). were calculated based on the heat capacity data in the temperature range from (80 to 400) K with an interval of 5 K. The standard molar enthalpies of combustion have been determined to be Delta H-c(m)0(C17H17NO4, s) = -(8308.52 +/- 3.22) kJ.mol(-1), with a precision oxygen-bomb combustion calorimeter at T = 298.15 K. The standard molar enthalpy of formation of the compound has been derived from the enthalpy of combustion, Delta H-f(m)0(C17H17NO4, s) = -(815.05 +/- 0.67) kJ.mol(-1). The thermal stability of Me compound was further studied using TG, and DSC, and a possible mechanism for thermal decomposition was suggested.

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.

The density and surface tension of the air- and water-stable hydrophobic ionic liquid (IL) 1-ethyl-3-methylimizazolium tris(pentafluoroethyl) trifluorophosphate (CAS Registry No.: 377739-43-0; [C2mim][PF3(CF2CF3)3]) were measured in the range of T = (283.15 to 338.15) K. The other physicochemical properties of the IL [C2mim][PF3(CF2CF3)3] at 298.15 K were estimated in terms of empirical and semiempirical equations, as well as the interstice model theory. These properties include molecular volume, standard molar entropy, lattice energy, the parachor, molar enthalpy of vaporization, interstice volume, thermal expansion coefficient, interstice fraction, and so forth. Then, the physicochemical properties of the ILs [Cnmim][PF3(CF2CF3)3] (n = 1, 3, 4, 5, 6) family were predicted in terms of the estimated values of molecular volume and the parachor.

A friendly environmental method was used to prepare a water-based hematite (α-Fe2O3) nanofluid through a simple biomolecule-assisted hydrothermal process. The molar heat capacities of the obtained nanofluids, base fluids, and hematite nanoparticles were measured by a high-precision automatic adiabatic calorimeter over the temperature range of (290 to 335) K, respectively. Polynomial equations of the molar heat capacities as a function of temperature were fitted by a least-squares method for the solid and nanofluid samples. Smoothed heat capacities and thermodynamic functions of the obtained samples, such as H(T/K) − H(298.15 K) and S(T/K) − S(298.15 K), were calculated on the basis of the fitted polynomials and the relationships of the thermodynamic functions. On the basis of the as-obtained molar heat capacities, the excess heat capacities of the nanofluids were calculated. These excess heat capacities reveal that the stable hematite nanofluids exhibit unique properties compared with the unstable one.

The activity coefficients at infinite dilution, γi∞, for both polar and nonpolar solutes in the ionic liquid 1-ethyl-3-methylimidazolium tris(pentafluoroethyl)trifluorophosphate ([EMIM][FAP]) have been determined by gas−liquid chromatography using the ionic liquid as the stationary phase. The measurements were carried out in the temperature range of (313 to 364) K. The partial molar excess enthalpies at infinite dilution HiE,∞ of the solutes in the ionic liquid were also derived from the temperature dependence of the γi∞ values.

Potassium hydrogen phthalate (KHP) was synthesized by the method of liquid-phase synthesis, in which phthalic acid and potassium hydroxide were chosen as the reactants. The structure and composition of the compound were characterized by chemical and elemental analyses, X-ray powder diffraction, and X-ray crystallography. 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 a least-squares method. The smoothed heat capacities and the thermodynamic functions of the compound relative to 298.15 K were calculated and tabulated at an interval of 5 K. In accordance with Hess’ law, a thermochemical cycle was designed. The enthalpy change of the reaction of phthalic acid with potassium acetate was determined to be ΔrHmo = −(4.298 ± 0.493) kJ·mol−1 by use of an isoperibol solution-reaction calorimeter, and the standard mola...

Different morphologies of beta-FeOOH including rod- and spindle-shaped crystals were synthesized via a hydrothermal reaction at low temperature. The molar heat capacities of the obtained samples were determined by a precision automated adiabatic calorimeter over the temperature range of (78 to 390) K. The observed results demonstrated that the change of the molar heat capacity with thermodynamic temperature was different for the rod and spindle-shaped beta-FeOOH crystals. Polynomial equations of the molar heat capacities as a function of temperature were fitted by a least-squares method for the rod- and spindle-shaped beta-FeOOH crystals. Smoothed heat capacities and thermodynamic functions of the obtained samples, such as H(T/K) - H(298.15) and S(T/K) - S(298.15), were Calculated on the basis of the fitted polynomials and the relationships of the thermodynamic functions. In addition, the as-prepared samples were also characterized by X-ray powder diffraction (XRD), transmission electron microscopy (TEM), and thermal gravimetric analysis (TGA).

The low-temperature heat capacity Cp,m of d-mannitol was measured in the temperature range from (80 to 390) K by means of a fully automated adiabatic calorimeter. The dependence of heat capacity on the temperature was fitted to a polynomial equation with the least-squares method. The thermodynamic functions (HT − H298.15 K) and (ST − S298.15 K) were derived from the heat capacity data in the temperature range of (80 to 390) K with an interval of 5 K. The melting temperature, molar enthalpy, and entropy of fusion were determined to be (437.25 ± 0.12) K, (54.69 ± 1.64) kJ·mol−1, and (125.08 ± 3.75) J·K−1·mol−1 by DSC measurements. The thermal stability and nonisothermal thermal decomposition kinetics of the compound were studied by the TG-DTG technique under atmospheric pressure and flowing nitrogen gas conditions. The thermal decomposition process had one mass loss stage, and the apparent activation energy Ea was obtained to be (120.61 ± 1.85) kJ·mol−1 by the Kissinger, Friedman, and Flynn−Wall−Ozawa metho...

Triaquabenzoatocalcium monobenzoate [Ca(Ben)(H2O)3](Ben)(s) was synthesized by the method of liquid phase reaction. Chemical and element analyses and X-ray crystallography were used to characterize the composition and structure of the complex. The lattice potential energy of the compound was calculated to be UPOT = 426.61 kJ·mol−1 on the basis of crystal structure information. Low-temperature heat capacities over the temperature range from (78 to 360) K were measured by an automated adiabatic calorimeter, and a polynomial equation was fitted by the least-squares method. On the basis of the fitted polynomial, the smoothed heat capacities and thermodynamic functions of the compound relative to the standard reference temperature 298.15 K were calculated at intervals of 5 K. The thermal decomposition of the complex was studied using TG and DSC analyses. In accordance with Hess’s law, a reasonable thermochemical cycle was designed based on the preparation reaction of the compound. The standard molar enthalpies...

Benzoic acid and barium hydroxide octahydrate were used as reactants, and a compound Ba(C7H5O2)2(s) was synthesized by the method of hydrothermal reaction. Chemical and elemental analyses, FTIR, and X-ray powder diffraction 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 (77 to 402) 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 on the basis of the fitted polynomial. The enthalpy change of the reaction of benzoic acid with barium hydroxide octahydrate was determined to be (22.03 ± 0.30) kJ·mol−1 by respective measuring enthalpies of dissolution of benzoic acid and Ba(C7H5O2)2(s) in 0.1 mol·dm−3 HCl and barium hydroxide octahydrate in 0.1 mol·dm−3 HCl solution containing certai...

Low-temperature molar heat capacities of the carbon nanotubes (CNTs) including single-walled carbon nanotubes (SWNTs) and multiwalled carbon nanotubes (MWNTs) were measured, respectively, by a precision automated adiabatic calorimeter over the temperature range of (78 to 398) K. The observed results demonstrated that the change in the molar heat capacity with thermodynamic temperature was different for the SWNTs and the MWNTs. Polynomial equations of the molar heat capacities as a function of the temperature were fitted by the least-squares method for SWNTs and MWNTs, respectively. Smoothed heat capacities and the changes in thermodynamic functions of the CNTs, such as ΔH = H(T/K) − H(298.15) and ΔS = S(T/K) − S(298.15), were calculated on the basis of the fitted polynomials and the relationships of the thermodynamic functions.

A novel compound, anhydrous calcium nicotinate Ca(Nic)2(s) (Nic = nicotinate), was synthesized by the method of room-temperature solid phase synthesis. FTIR, chemical, and elemental analyses and an X-ray powder diffraction technique were applied to characterize the structure and composition of the complex. Low-temperature heat capacities of the solid coordination compound have been measured by a precision automated adiabatic calorimeter over the temperature range from T = 78 K to T = 400 K. The experimental values of the molar heat capacities in the temperature regions of (78 ∼ 400) K were fitted to one polynomial. The polynomial fitted values of the molar heat capacities and fundamental thermodynamic functions of the sample relative to the standard reference temperature 298.15 K were calculated and tabulated at intervals of 5 K. In accordance with Hess’ law, a thermochemical cycle was designed; the enthalpy change of the solid phase reaction of nicotinic acid with calcium hydroxide was determined to be Δ...

The heat capacities of (3,4-dimethoxyphenyl) acetonitrile were measured by a small sample precision automated adiabatic calorimeter over the temperature range from (78 to 399) K. A melting phase tr...

Nicotinic acid and cadmium chloride were used as the reactants, absolute ethanol as solvent, and a novel coordination compound Cd(HNic)2Cl2 was synthesized by the method of liquid phase reaction. Chemical and elemental analyses, FTIR, and X-ray powder diffraction techniques were applied to characterize its composition and structure. Low-temperature heat capacities of the solid coordination compound have been measured by a precision automated adiabatic calorimeter over the temperature range from T = 78 K to T = 400 K. The experimental values of the molar heat capacities in the temperature region were fitted to a polynomial. Smoothed heat capacities and thermodynamic functions of the complex relative to 298.15 K were calculated based on the fitted polynomial and tabulated at 5 K intervals. In accordance with Hess’s law, a reasonable thermochemical cycle was designed based on the preparation reaction of the new substance, and 100 mL of 0.1 M HCl solution was chosen as the calorimetric solvent. The standard m...

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 capacities of the solid coordination compound Cr(C6H4NO2)3(s) have been measured by a precision automated adiabatic calorimeter over the temperature range T = 78 K to T = 391 K. The experimental values of the molar heat capacities in the temperature region were fitted to a polynomial equation of heat capacities (Cp,m) with the reduced temperatures (X), [X = f(T)], by a least-squares method. The smoothed molar heat capacities and thermodynamic functions of the complex Cr(C6H4NO2)3(s) were calculated based on the fitted polynomial. The smoothed values of the molar heat capacities and fundamental thermodynamic functions of the sample relative to the standard reference temperature 298.15 K are tabulated with an interval of 5 K. Enthalpies of dissolution of {3C6H5NO2(s)} [ΔdHm⊖(1)] and Cr(C6H4NO2)3(s) [ΔdHm⊖(3)] in 100.00 mL of 0.1 mol·dm−3 HCl and {Cr(OH)3(s)} [ΔdHm⊖(2)] in 100.00 mL of 0.1 mol·dm−3 HCl solution containing certain amounts of nicotinic acid (named as solution A1) at T = 29...

The molar heat capacities of the aqueous Li2B4O7 solution at the concentration of 0.0187 mol.kg(-1) have been measured using a precision automated adiabatic calorimeter in the temperature range from 80 K to 355 K. The dependence of the molar heat capacity on temperature was given as a function of the reduced temperature X by polynomial equations C-p,C-m (J.K-1.mol(-1)) = 25.44 + 11.99X + 0.454X(2) + 1.671X(3) for the solid phase [80 K similar to 258 K, X = (T - 169)/89] and C-p,C-m (J.K-1.mol(-1)) = 77.33 for the liquid phase [274 K similar to 355 K], respectively. The phase transition of the solution was determined on the basis of the curve of the heat capacity with temperature. The temperature of the phase transition was observed at 273.04 K, and the enthalpy and entropy of the phase transition were calculated to be Delta H-m = 4.650 kJ.mol(-1) and Delta S-m = 17.03 J.K-1.mol(-1), respectively. According to the polynomial equations and thermodynamic relationship, the values of the thermodynamic function of the aqueous Li2B4O7 solution relative to 298.15 K were calculated in the temperature range from 80 K to 355 K with an interval of 5 K. The relative apparent molar heat capacities of the aqueous Li2B4O7 solution, C-p,C-phi, were calculated every 5 K in the temperature range from 80 K to 355 K from the experimental heat capacities of the aqueous Li2B4O7 solution and the heat capacities of pure water. The molar heat capacities of the aqueous Li2B4O7 solution at the concentration of 0.0187 mol.kg(-1) have been measured using a precision automated adiabatic calorimeter in the temperature range from 80 K to 355 K. The dependence of the molar heat capacity on temperature was given as a function of the reduced temperature X by polynomial equations C-p,C-m (J.K-1.mol(-1)) = 25.44 + 11.99X + 0.454X(2) + 1.671X(3) for the solid phase [80 K similar to 258 K, X = (T - 169)/89] and C-p,C-m (J.K-1.mol(-1)) = 77.33 for the liquid phase [274 K similar to 355 K], respectively. The phase transition of the solution was determined on the basis of the curve of the heat capacity with temperature. The temperature of the phase transition was observed at 273.04 K, and the enthalpy and entropy of the phase transition were calculated to be Delta H-m = 4.650 kJ.mol(-1) and Delta S-m = 17.03 J.K-1.mol(-1), respectively. According to the polynomial equations and thermodynamic relationship, the values of the thermodynamic function of the aqueous Li2B4O7 solution relative to 298.15 K were calculated in the temperature range from 80 K to 355 K with an interval of 5 K. The relative apparent molar heat capacities of the aqueous Li2B4O7 solution, C-p,C-phi, were calculated every 5 K in the temperature range from 80 K to 355 K from the experimental heat capacities of the aqueous Li2B4O7 solution and the heat capacities of pure water.

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.

The molar heat capacity, C-p,C-m, of a complex of erbium chloride coordinated with L-proline, [Er(Pro)(2)(H2O)(5)]Cl-3, was measured from T) 80 K to T) 400 K with an automated adiabatic calorimeter. The temperature, the molar enthalpy, and the entropy of fusion and decomposition were calculated using equations and diagrammatic area integration. The thermodynamic functions [H-T-H-298.15] and [S-T-S-298.15] were derived from T = 80 K to T = 360 K with a temperature interval of 5 K. The thermal stability of the compound was investigated by differential scanning calorimetry and the thermogravimetric techniques.

Low-temperature heat capacities of the solid coordination compound Zn(Leu)SO(4)center dot 1/2H(2)O(s) were measured by a precision automated adiabatic calorimeter over the temperature range between T = 78 K and T = 371 K. The initial dehydration temperature of the coordination compound was determined to be T-D = 326.50 K by analysis of the heat-capacity curve. The experimental values of molar heat capacities were fitted to a polynomial equation of heat capacities (C-p,C-m) with the reduced temperatures (x), [x = f (T)] by least-squares method. Enthalpies of dissolution of the [ZnSO(4)center dot 7H(2)O(s) + Leu(s)] ( Delta(sol)H degrees(m,1)) and the Zn(Leu)SO(4)center dot 1/2H(2)O(s) (Delta(sol)H degrees(m,2)) in 100.00 mL of 2 mol center dot dm(-3) HCl(aq) at T = 298.15 K were determined to be Delta solH degrees(m,1) = -(85.80 +/- 0.09) kJ center dot mol(-1) and Delta solH(m,2) = (55.97 +/- 0.06) kJ center dot mol(-1) by means of a homemade isoperibol solution-reaction calorimeter. The standard molar enthalpy of formation of the compound was determined as Delta H degrees(m)(Zn(Leu)SO(4)center dot 1/2H(2)O, s, 298.15 K) = -(1999.0 +/- 0.9) kJ center dot mol(-1) from the enthalpies of dissolution and other auxiliary thermodynamic data through a Hess thermochemical cycle. Furthermore, the reliability of the Hess thermochemical cycle was verified by comparing UV/Vis spectra and the refractive indexes of solution A (from dissolution of the [ZnSO(4)center dot 7H(2)O(s) + Leu(s)] mixture in 2 mol center dot dm(-3) hydrochloric acid) and solution A' (from dissolution of the complex Zn(Leu)SO(4)center dot 1/2H(2)O(S) in 2 mol center dot dm(-3) hydrochloric acid).

The molar heat capacity Cp,m of 4-methyl-4-cyclohexene-1,2-dicarboxylic anhydride was measured over the temperature range from T = 80 K to T = 361 K with a small-sample automated adiabatic calorimeter. The melting point Tm and the molar enthalpy ΔfusHm and entropy ΔfusSm of fusion for the compound were determined to be (335.54±0.41) K, (17.67±0.04) kJ·mol-1, and (52.65±0.04) J·K-1·mol-1, respectively. Thermodynamic functions [HT − H298.15] and [ST − S298.15] were derived in the temperature range from T = 80 K to T = 361 K with a temperature interval of 5 K. The purity of the sample in mole fraction used in the adiabatic calorimetry study was determined to be 0.9940 by using the fractional melting technique. The thermal stability of the compound was investigated by differential scanning calorimetry (DSC) and a thermogravimetric (TG) technique, and the process of the mass loss of the sample was due to evaporation instead of thermal decomposition.

The molar heat capacities of 2-(chloromethylthio)benzothiazole (molecular formula C8H6ClNS2, CA registry no. 28908-00-1) were measured with an adiabatic calorimeter in the temperature range between (80 and 350) K. The construction and procedures of the calorimeter were described in detail. The performance of the calorimetric apparatus was evaluated by heat capacity measurements on α-Al2O3. The deviation of experiment heat capacities from the corresponding smoothed values lies within ±0.3%, whereas the uncertainty is within ±0.5%, compared with that of the recommended reference data over the whole experimental temperature range. A fusion transition was found from the Cp−T curve of 2-(chloromethylthio)benzothiazole. The melting temperature and the molar enthalpy and entropy of fusion of the compound were determined to be Tm = (315.11 ± 0.04) K, ΔfusHm = (17.02 ± 0.03) kJ·mol-1, and ΔfusSm = (54.04 ± 0.05) J·mol-1·K-1, respectively. The thermodynamic functions (HT − H298.15) and (ST − S298.15) were also deri...

Molar heat capacities of the azeotropic mixture in the binary system {water (x = 0.568) + n-propanol (x = 0.432)}were measured with an adiabatic calorimeter in the temperature range from (80 to 320) K. The functions of the heat capacity with respect to the thermodynamic temperature were established. A glass transition was observed at 102.037 K. The solid−liquid-phase transition of the azeotropic mixture took place in the temperature range from (237.075 to 262.424) K. The corresponding enthalpy and entropy of the solid−liquid-phase transition were calculated to be 5.869 kJ·mol-1 and 22.73 J·K-1·mol-1, respectively. The thermodynamic functions and the excess thermodynamic functions of the azeotropic mixture relative to a temperature of 298.15 K were derived on the basis of the relationships of the thermodynamic functions and the function of the measured heat capacity with respect to temperature.

An isoperibol solution−reaction calorimeter suitable for measuring molar enthalpies of solid−liquid and liquid−liquid interactions was constructed. The volume of calorimetric vessel made by transparent hard glass is about 100 cm3. Its energy equivalent is 0.48 kJ·K-1 when containing 100 cm3 of double distilled water. The thermal leakage modulus is 2.7 × 10-4 s-1. The time constant of the calorimeter is about 2.9 s. The precision of controlling and measuring the temperature is within ±0.001 K and ±0.0001 K, respectively. The performance of the calorimeter was tested by measuring the enthalpy of dissolution of KCl in double distilled water, Δs = (17 547 ± 13 J·mol-1) at T = (298.15 ± 0.001) K, and the measuring uncertainty was estimated to be within ±0.30% by comparing our measured value with the reference. Molar enthalpies of dissolution of the {ZnCl2(s) + l-His(s)} mixture and the complex Zn(His)Cl2·1/2H2O(s) in 100 cm3 of 2 mol·L-1 HCl at T = (298.15 ± 0.001) K have been measured to be Δd = (26.419 ± 0.0...

Density and surface tension of the air- and water-stable hydrophobic ionic liquids N-alkylpyridinium bis(trifluoromethylsulfonyl)imide ([Cnpy][NTf2], n = 2, 4, 5) were measured in the temperature range T = (283.15 to 338.15) K. The melting temperatures of the samples were determined by differential scanning calorimetry (DSC). Decomposition temperatures are higher than 600 K as determined by thermogravimetric analysis (TG).

Molar heat capacities (Cp,m) of the room-temperature ionic liquid (IL) 1-propyl-3-methylimidazolium glutamic acid salt ([C3mim][Glu]) were measured with a high-precision automated adiabatic calorimeter (AC) in the temperature range of T = (85 to 360) K. A glass transition was observed at 239.861 K. The enthalpy and entropy of the glass transition were determined to be 2.87 kJ·mol−1 and 11.97 J·K−1·mol−1, respectively. Two polynomial equations of molar heat capacity as a function of the temperature were fitted before and after the glass transition. The thermodynamic functions (HT − H298.15) and (ST − S298.15) were derived from the molar heat capacity data in the temperature range of T = (85 to 360) K with an interval of 5 K.

The low-temperature heat capacities of trans-4-(aminomethyl)cyclohexanecarboxylic acid were measured with an adiabatic calorimeter over the temperature range from (82 to 378) K. The heat capacity curve was smooth and continuous, which indicated that the compound was stable over the whole temperature range. Thermal decompositions of the compound were studied by thermogravimetry (TG) and the possible mechanism of the thermal decomposition was deduced. The energy of combustion of the compound was determined, and the standard enthalpy of combustion, ΔcHϑ, and standard enthalpy of formation, ΔfHϑ, were calculated.