Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Gibbs free energy various forms

  1. Sep 2, 2015 #1
    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. jcsd
  3. Sep 2, 2015 #2

    Titan97

    User Avatar
    Gold Member

    ##\Delta G^0## is constant at all conditions. Its ##\Delta G## that changes with change in conditions.
     
  4. Sep 3, 2015 #3
    What about ΔG°' ?
     
  5. Sep 3, 2015 #4

    Titan97

    User Avatar
    Gold Member

    Where did you read it?
     
  6. Sep 3, 2015 #5
    It was given in the question of our assignment.
     
  7. Sep 3, 2015 #6
    May be something like the conditions that are common in your field of science, say pH is 7 and temp is 36 °C.
     
  8. Sep 4, 2015 #7
    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
     
  9. Sep 5, 2015 #8
    He didn't ask about that.
     
  10. Sep 5, 2015 #9
    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
     
  11. Sep 5, 2015 #10
    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
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook




Similar Discussions: Gibbs free energy various forms
  1. Gibbs Free Energy. (Replies: 1)

Loading...