Gibbs free energy various forms

1. Sep 2, 2015

Raghav Gupta

What is the difference between 1) ΔG°' and ΔG°
and 2) ΔG°' and ΔG ?
ΔG° I think it is the gibbs free energy at standard state means at room temperature 1 atm pressure.

2. Sep 2, 2015

Titan97

$\Delta G^0$ is constant at all conditions. Its $\Delta G$ that changes with change in conditions.

3. Sep 3, 2015

4. Sep 3, 2015

5. Sep 3, 2015

Raghav Gupta

It was given in the question of our assignment.

6. Sep 3, 2015

Alcathous

May be something like the conditions that are common in your field of science, say pH is 7 and temp is 36 °C.

7. Sep 4, 2015

Staff: Mentor

ΔG0 is the change in free energy between state 1 and state 2, where

State 1: Stoichiometric quantities of pure reactants in separate containers, each at temperature T and 1 atm pressure

State 2: Corresponding stoichiometric quantities of pure products in separate containers, each at temperature T and 1 atm pressure

So ΔG0 is a function of temperature.

Chet

8. Sep 5, 2015

9. Sep 5, 2015

Staff: Mentor

What do the words "ΔG° I think it is the gibbs free energy at standard state means at room temperature 1 atm pressure." mean to you?

Chet

10. Sep 5, 2015

Staff: Mentor

I've never seen ΔG0' used before, but, apparently ΔG0' is the value of ΔG0 at 25 C (see post #7).

Incidentally, regarding ΔG, this is the change in free energy if the pressures of the pure species in States 1 and 2 (see post #7) are not all equal to 1 atm.

Chet