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.

APPLICATIONS OF A NEW TOPOLOGICAL INDEX EDm IN SOME ALIPHATIC HYDROCARBONS

Abstract: A novel index EDm based on ionicity index matrix, improved distance matrix, and branching degree matrix is used to describe the structural information of the molecule and realizes unique characterization of the molecular structures. The quantitative structure–property relationship (QSPR) models, with correlation coefficients (R) in the range of 0.99–1.00 for standard enthalpy of formation (), standard entropy (), molar volume (Vm), and molar refraction (Rm) of alkanes, alkenes, and alkynes, are subsequently developed using the index EDm. The leave-one-out (LOO) method and random sampling prediction (RSP) method demonstrate the models to be statistically significant and reliable. Compared with other published topological descriptors, the index EDm has many advantages such as zero degeneracy, better simulation, and so on. Furthermore, the models of solubility and octanol–water partition coefficient are built with satisfied results, which further manifests the superiority and wide application of this index.

Thermodynamic behavior of fish meal during adsorption

Abstract: Anchovy fish meal with an approximate uniform moisture content of 10% was used for this study. Vapor adsorption isotherms were determined at 25 ° C, 35 ° C and 45 ° C. The differential and integral thermodynamic properties were estimated using the Othmer method. The isosteric heat or differential enthalpy, as a function of moisture content, showed a maximum value around 4.5 g of water/100 g d. s. The heat of sorption increased gradually with an increase in sorbed water until reaching its maximum value near the monolayer, and at a given moisture content, decreasing with temperature. The molar entropy values obtained were high at low water contents and fell to a minimum near the monolayer value.

Thermodynamic Study of 8‐Hydroxyquinoline by Adiabatic Calorimetry and Thermal Analysis

Abstract: A calorimetric study and thermal analysis for 8-hydroxyquinoline were performed The low-temperature heat capacity of this compound was measured with a precise automated adiabatic calorimeter over the temperature range from 78 to 370 K The melting point T(fus), molar enthalpy Delta(fus)H(m) and molar entropy Delta(fus)S(m) of fusion of this substance were determined to be (34574 +/- 015) K, (1393 +/- 011) kJ center dot mol(-1) and (4026 +/- 033) J center dot K(-1)center dot mol(-1), respectively The thermodynamic functions of the substance, such as molar enthalpy and entropy of fusion, and thermodynamic functions [H(T)-H(29815)] and [S(T)-S(29815)] were derived from two polynomial equations of the experimental molar heat capacities against the reduced temperature fitted by the least square method The melting temperatures for the sample and the absolutely pure compound have been obtained from fractional melting experiments to be 345601 and 345761 K, respectively, and the molar fraction purity of the sample was calculated to be 09978 according to the van't Hoff equation The thermal stability of the compound was further investigated by differential scanning calorimetry (DSC)