Chemical species can be characterized by various observable features: mass, enthalpy of formation, charge (ions), dipole moment, magnetic susceptibility, electrical susceptibility, electromagnetic spectra, refr
The Gibbs energy of mixing is composed of an enthalpic and entropic component, ΔmixHm and ΔmixSm, respectively, with a similar definition. In the case of an ideal solution, the entropy of mixing is given by:(5)ΔmixSmideal=-R∑ixilnxiand the enthalpy of mixing is equal to zero, wh...
The relationship between the two common measures of tropical cyclone intensity, the central pressure deficit and the peak near-surface wind speed, is a long-standing problem in tropical meteorology that has been approximated empirically yet lacks physical understanding. Here we provide theoretical groundi...
The enthalpy changes (ΔH), apparent activation energy (Ea, app), and intrinsic activation energy (Ea, int) are dependent on interactions with the solvent environment. Full size image In this work, attenuated total reflection (ATR)-FTIR is used to measure liquid-phase pyridine adsorption ...
here is the reaction: Ba(OH)2*8H2O(s) + 2NH4Cl(s) = BaCl2(aq) + 2NH3(g) + 10H2O(l) What i am having problems with understanding are the terms entropy (not so much, i think i pretty much know this), enthalpy, and free energy relating to this reaction. ...
In this work, the considered endpoints are the enthalpy of formation and the absolute entropy for the ideal gas state of molecules at 298.15 K and 1 bar. For simplicity, they will be henceforth, respectively, denoted as enthalpy (H) and entropy (S). For each molecule of the database, th...
From the definition of the vaporization entropy,(1)ΔHVTb=ΔSV ΔHVis the vaporization enthalpy at the boiling point under 1/atm pressure. ΔSV is the vaporization entropy at the boiling point under 1/atm pressure. Empirically it was found that for many nonpolar compounds ΔSV≅88.2/j...
Current chemistry curricula split the thermodynamic chapters over a span of two semesters as well as splitting it over different units. This division fails to make explicit the connection between Enthalpy, Entropy and Gibbs Energy and how they affect how and why every reaction or process happens. ...
The year 2015 marked the 150th anniversary of this definition, but it continues to be a confusing concept in thermodynamics. It is one of the challenges encountered in the attempt to reconcile the microscopic view of matter offered by statistical thermodynamics with the macroscopic view of ...
In the present work, a multi-angle approach is adopted to develop two ML-QSPR models for the prediction of the enthalpy of formation and the entropy of molecules, in their ideal gas state. The molecules were represented by high-dimensional vectors of structural and physico-chemical characteristics...