Topic
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.
Papers published on a yearly basis
Papers
More filters
Journal Article•
TL;DR: In this article, the standard molar enthalpy of formation, standard entropy and isobaric molar heat capacity of propylene dimerization products were estimated by using Benson group contribution method and ABWY method.
Abstract: The standard molar enthalpy of formation, standard entropy and isobaric molar heat capacity of propylene dimerization products were estimated by using Benson group contribution method and ABWY method. The enthalpy change, Gibbs free energy change and equilibrium constant of propylene dimerization to 4-methyl-1-pentene reaction system were calculated in detail as a function of the temperature from 298K to 700K. The thermodynamic equilibrium and the limit of different reaction steps were analyzed. The thermodynamic possibility and formation sequences of propylene dimerization reaction system were also judged. The effects of temperature and pressure on the equilibrium conversion were investigated. The equilibrium conversions of propylene dimerization reactions in the specific process condition were obtained according to thermodynamic calculations. The results showed that propylene dimerization is an exothermic reaction, which is spontaneous at low temperature and can reach to a deep extent. Low temperature and high pressure are favored to propylene dimerization to 4-methyl-1-pentene reaction from a thermodynamic point of view. The occurrences of the other side reactions are easier than propylene dimerization to 4-methyl-1-pentene except to 1-hexene. The appropriate process conditions are 400K-450K, 8MPa-15MPa. The equilibrium conversions of all propylene dimerization reactions approach 100% at 428K, 10MPa.
1 citations
TL;DR: In this article, the determined thermodynamic properties were found to be inconsistent and do not abide by the thermodynamics-related association (∆G = ∆H - T∆S), and molar entropy do not to observe thermodynamic law of S = − (∂G/∂T)P.
1 citations
01 Apr 1978
TL;DR: The tritium equation of state, extended from measurements of the lighter hydrogen isotopes, was used to derive thermodynamic properties of Tritium fluid as mentioned in this paper, including the isobaric thermal expansion coefficient, the molar heat capacity at constant pressure C/sub p/, adiabatic compressibility coefficient chi/sub s/, heat capacity ratio, and molar entropy S. Computer-drawn graphs of these variables vs pressure along five isotherms are shown.
Abstract: The tritium equation of state, extended from measurements of the lighter hydrogen isotopes, is used to derive thermodynamic properties of tritium fluid. Tabular values are given at rounded kbar pressures and 25/sup 0/K temperature intervals in the range 75 to 300/sup 0/K and 2 to 20 kbar. Included are the isobaric thermal expansion coefficient ..cap alpha../sub p/, the molar heat capacity at constant pressure C/sub p/, adiabatic compressibility coefficient chi/sub s/, heat capacity ratio ..gamma.., and molar entropy S. Computer-drawn graphs of these variables vs pressure along five isotherms are shown.
1 citations
TL;DR: In this article, an empirical equation was proposed to describe the viscosity B coefficients for dilute solutions of nonelectrolytes in water, which is based on the empirical equation developed for nonaqueous mixtures and an assumption that the entropy change on solution of the liquid solute on the aqueous system in the same way as a change of molar entropy on pure water.
Abstract: An equation is proposed to describe the viscosity B coefficients for dilute solutions of nonelectrolytes in water. It is based on an empirical equation developed for nonaqueous mixtures and an assumption that the entropy change on solution of the liquid solute affects the viscosity of the aqueous system in the same way as a change of molar entropy affects the viscosity of pure water. The equation is shown to represent experimental results well and is especially successful in representing the temperature dependence of the B coefficient for aqueous solutions of alcohols.
1 citations
01 Jan 2003
TL;DR: Based on the relationship between partition function and entropy in statistical thermodynamics for a distinguishable particle system, the atomic weight (A_(r,i)) and electronic shell number(n_i) of ground state atom i has an excellent correlativity with the standard entropies.
Abstract: Based on the relationship between partition function and entropy in statistical thermodynamics for a distinguishable particle system, the atomic weight (A_(r,i)) and electronic shell number(n_i) of ground state atom i has an excellent correlativity with the standard entropies \{[S~0_m/(J·mol~(-1)·K~(-1))]\} of 70 cations in solid compounds: S~0_m=(-0.51)+(3.59)·((1.5\}ln A_(r,i))~(1.4)-\{0.31(ln\} n_i)~2, R=(0.999 6.) Based on the relationship between enthalpy and partition function for an indistinguishable particle system, the linear regression equation between ground state energies (e_i) and hydrated enthalpies[-Δ_hH_m/(kJ·mol~(-1))] of 51 metal ions is drawn up: -Δ_hH_m=46.93+525.49e_i, R=(0.992 0). The calculated values of S~0_m, (Δ_hH_m) basically tally with the experiment values.
1 citations