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Standard molar entropy
About: Standard molar entropy is a research topic. Over the lifetime, 1586 publications have been published within this topic receiving 29886 citations.
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TL;DR: In this article, the equilibrium constant of the isomerization reaction between d-mannose and d-fructose which is catalyzed by a mannose isomerase from Streptomyces aerocolorigenes was obtained by using three methods over the temperature range from 1 to 40°C.
Abstract: The equilibrium constant of the isomerization reaction between d-mannose and d-fructose which is catalyzed by a mannose isomerase from Streptomyces aerocolorigenes was obtained by using three methods over the temperature range from 1 to 40°C.It was found that the equilibrium constant was scarcely dependent on temperature, ΔH, the heat of the formation of d-fructose from d-mannose, being approximately zero.The standard free energy change, ΔG, and the standard entropy change, ΔS, of the reaction were calculated from the equilibrium constants at various temperatures and ΔH. The values of ΔG and ΔS at 25°C were −650 cal/mole and + 2.2 cal/deg·mole, respectively.By combining these thermodynamic data with those obtained for the isomerization reaction between d-glucose and d-fructose reported in the previous paper, ΔH, ΔG and ΔS for the isomerization between d-mannose and d-glucose were indirectly obtained to be +2220 cal/mole, +830 cal/mole and +4.6 cal/deg·mole at 25°C, respectively.
25 citations
TL;DR: In this paper, the heat capacity of solid carbon tetrachloride was measured between 3 and 50 K and the standard entropy for the gas was revised to (742 ± 03) cal K−3 mol−1 in comparison with the spectroscopic entropy of 7403 cal k−1mol−1 at 25°C.
25 citations
TL;DR: In this article, the heat capacity of bis(4-chlorophenyl)sulfone was measured from the temperature T = 14 to T = 300 K by adiabatic calorimetry, and an incommensurate phase transition was detected as a second-order type of heat capacity anomaly at T = (148.5 ± 0.5) K.
25 citations
TL;DR: In this article, the experimental results for the pure components were fitted to empirical equations, which permit the calculation of these properties in the studied temperature range, and data of the binary mixture were further used to calculate the excess molar volume and viscosity deviations.
Abstract: Density and viscosity measurements in the T = (273.15 to 318.15) K range of pure chloroform and methyl tert-butyl ether (MTBE), as well as of the binary system [x1 chloroform + (1 − x1) MTBE] over the whole concentration range at T = 293.15 K, were made. The experimental results for the pure components were fitted to empirical equations, which permit the calculation of these properties in the studied temperature range. Calculated values are in agreement with the experimental ones. Data of the binary mixture were further used to calculate the excess molar volume and viscosity deviations. The excess molar enthalpy at T = (303 ± 1) K and vapor−liquid equilibrium measurements at T = (303.15 ± 0.05) K were also measured for the binary system. These last experimental results were used to calculate activity coefficients, the excess molar Gibbs energy, and excess molar entropy. This binary system shows strong negative deviations from ideality and exhibits a minimum pressure azeotrope, whose coordinates are: P = (...
24 citations
TL;DR: In this article, the authors investigated the thermal conductivity, Young's modulus, Debye temperature, Vickers hardness, and heat capacity of Th1−x U x O2 solid solutions.
Abstract: Th1−x U x O2 solid solutions were synthesized by solid-state reaction and pelletized using the spark plasma sintering (SPS) technique. Pellets with >90% theoretical density were easily obtained within 40 min of sintering without any additive. The thermal conductivity, Young's modulus, Debye temperature, Vickers hardness, and heat capacity were systematically investigated, and the values for ThO2 agree with the literature data. The thermal conductivity of Th1−x U x O2 decreased with increasing U content up to x =∼0.5. This tendency corresponds to phonon-point defect scattering theory. The Young's modulus and Debye temperature linearly decreased with increasing U content. The Debye temperature and standard molar entropy derived from the low-temperature heat capacity agree with the reported values.
24 citations