by admin | Jun 4, 2015 | sem1
One Component System For pure substances C = 1 so that F = 3 – P. In a single phase (P = 1) condition of a pure component system, two variables (F = 2), such as temperature and pressure, can be chosen independently to be any pair of values consistent with the phase....
by admin | Jun 4, 2015 | sem1
Gibbs Helmholtz equation Recall that the combined first and second laws give the relationship (1) This implies that U is a function of S and V. Sometimes we call S and V the “natural variables” of U. Regarding U = U(S,V) we can write...
by admin | Jun 4, 2015 | sem1
Gibbs free energy In thermodynamics, the Gibbs free energy (IUPAC recommended name:Gibbs energy or Gibbs function; also known as free enthalpy[1] to distinguish it from Helmholtz free energy) is a thermodynamic potential that measures the “usefulness” or...
by admin | Jun 4, 2015 | sem1
Helmholtz free energy In thermodynamics, the Helmholtz free energy is a thermodynamic potentialthat measures the “useful” work obtainable from a closed thermodynamic system at a constant temperature. The negative of the difference in the Helmholtz energy is equal to...
by admin | Jun 4, 2015 | sem1
Clausius Inequality The Clausius theorem (1855) states that for a system exchanging heat with external reservoirs and undergoing a cyclic process (i.e. a process which ultimately returns a system to its original state): where δ is the amount of heat absorbed by the...
by admin | Jun 4, 2015 | sem1
Entropy of Phase Transitions We would expect that a phase change would be accompanied by a change in entropy. For example, when a liquid boils, a compact condensed phase is converted into a widely dispersed vapour phase. Clearly, the molecular disorder in a gas will...
