The absolute entropy of a pure substance at 25°C (298 K) and 1 atm pressure is called the standard entropy, S°. The standard entropies of all substances either elements or compounds at any temperature above…

Characteristics of Free energy ‘G’ i) G is defined as (H-TS) where H and S are the enthalpy and entropy of the system respectively. T = temperature. Since H and S are state functions, G…

Gibbs Free Energy ‘G’: According to II law of thermodynamics, inorder to predict the spontaneity of a process entropy of universe is considered. ΔSunivers is the sum of ΔSsystem and ΔSsurroundings. It is difficult to…

Entropy increase in a process a) In a chemical reaction, when number of molecules of products are more than the number of molecules of reactant entropy increases. b) In physical process, when a solid changes…

Standard Free Energy (G°): Like standard enthalpy of formation of substances, standard enthalpy change of a reaction, standard free energy of formation of substances and standard free energy change of reactions are considered. The standard…

Entopy change in a physical (phase) transformation can be determined particularly for evaporation of liquids at the boiling points, using Trouton’s rule. According to this rule, the heat of vaporization (ΔHvap)in calories per mole divided…

The ability of certain ultra cold substances to conduct electricity without resistance is called super conductivity. This superconductivity state is a state in which a material has virtually zero electrical resistance. Substances having this property…