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standard formation entropy

• For pure element molecules, the standard formation of free energy and enthalpy are set to 0 (since we only care about relative).

• For entropy, however, we use 0K as the reference, so that the absolute entropy of any substance can be measured from Cp vs. T: S(T)=S(0)+integral (Cp/T).

• For example, H2 (g)'s standard state absolute entropy (relative to 0K) is 130.6 J/mol K. The standard formation entropy (130.6-130.6) is still 0. The standard formation enthalpy, free energy, and entropy of H2 are all 0.

• List of values: http://www.wiredchemist.com/chemistry/data/entropies-inorganic