What is Gibbs Free Energy?

How do I add the pressure to the equation to find the Gibbs free energy formation?

• Estimate the ΔGo for the following reaction. What is ΔGo at 298 K if p = 0.25 bar for each gaseous substance in the above Reaction. 1) 2 H2(g) + O2(g) ---> 2 H2O(l) 2) C(s, graphite) + 2 H2(g) ---> CH4(g) 1) I used the formula Gibbs free energy = (enthalpy formation) - T(entropy formation) The answer I got (when I don't include the pressure) is -227.42KJ/mol 2) Same equation from number one, I got -64.90KJ/mol The problem I'm having is how do I incorporate the pressure of 0.25 bars into the equation of Gibbs free energy?

• Answer:

  U have to use another equation. U already calc first G, so use that in the eq below K=e^[G/RT ] G=RTlnK