Question

What standard conditions do we assume when calculating the standard free energy of formation?

Answer 1

The standard Gibbs free energy of formation of a compound is the change of Gibbs free energy that accompanies the formation of 1 mole of that substance from its component elements, at 25 degrees Celsius and 101.3 kilopascals (or 1 atm).

The standard conditions other than 25 degree celsius are

1. For a gas: the standard state is a pressure of exactly 1 atm
2. For a solute present in an ideal solution: a concentration of exactly one mole/liter (M) at a pressure of 1 atm
3. For an element: the form in which the element is most stable under 1 atm of pressure.