In kinetics, activation parameters could be evaluated using both Arrhenius and Eyring equations. As an example the modern view of entropy is well described by Frank L. The change in thermodynamic quantities could be interpreted in terms of classical thermodynamic principles. Marcus equation 5, 6, 7 is a successful treatise for treating kinetic data of electron transfer reactions to separate activation (ΔX ≠) and thermodynamic quantities (ΔX o). The nature of any property accompanied in chemical reactions in terms of energy considerations is nothing but an amalgamation of activation barrier (ΔX ≠) and thermodynamic driving force (ΔX o). As shown in the Figure 2, as an example taking any property (X = G free energy, or H enthalpy, or S entropy), thermodynamic and activation parameters could be distinguished between thermodynamics and kinetics. Thermodynamic properties like enthalpy, free energy and entropy of several thousands of organic and organometallic compounds were well documented and a very authoritative explanations and expert critical comments were offered 3, 4. In this article making use of Eyring equation a factor usually called ‘ universal factor’ is derived and made use as a ‘ yard stick’ to interpreting the change in entropy of activation for physical or physical-organic chemistry senior undergraduate and graduate students’ class-room. The two environments are analogues of high and low temperatures, respectively. The classical thermodynamic entropy change is well explained by Atkins in terms of a sneeze in a busy street generates less additional disorder than the same sneeze in a quiet library (Figure 1). When it comes to interpretation of change of entropy or change of entropy of activation, more often it frightens than enlightens a new teacher while teaching and the students while learning. Most often it is very easy to interpret the enthalpy change and free energy change in thermodynamics and the corresponding activation parameters in chemical kinetics. The only way to evaluate all the thermodynamic or activation parameters is the use of some empirical equations available in many physical chemistry text books. But when it comes to the turn of thermodynamic or activation parameters, we don’t have any meters. To measure conductance we use conductometer, pH meter for measuring pH, colorimeter for absorbance, viscometer for viscosity, potentiometer for emf, polarimeter for angle of rotation, and several other instruments for different physical properties. It is exactly the entropy increase in the entire system that allowed the entropy in the part of the system to decrease thus producing life, evolution, and ultimately intelligence.No physical or physical-organic chemistry laboratory goes without a single instrument. Without this constant entropy increase, life on Earth would be impossible. Such a reduction of the entropy as the emergence of life and its evolution on Earth was possible exactly because Earth alone is not a closed system, but a conduit of a tremendous entropy increase of the solar energy dissipating as heat. In this sense biological life and evolution represent a highly organized matter and therefore a low entropy. Entropy is often referred to as a measure of chaos, so order would be the opposite of entropy. However, the entropy on Earth alone can indeed decrease. The entropy of the whole (closed) system (Sun, Earth, and space) always increases. For example, Earth receives the solar energy prom the Sun and dissipates it into space as heat. Yes, absolutely! The entropy can decrease for a system that is not closed. In this sense your question would be if the entropy of a system can decrease. I think what you mean is that the entropy doesn't change for reversible processes, but increases for irreversible processes.
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