How is #K_(eq)# related to #DeltaG^@#?

1 Answer

Answer:

If we know the equilibrium constant, #K_(eq)#, for a chemical change we can calculate the standard state free energy change, #Delta G^@#.

Explanation:

The "free energy" change for a reaction may determine whether it will be spontaneous or not, but "equilibrium" is just the final state of a system. The equations may be solved either way, depending on the available data (equilibrium concentrations or energy change).

If we know the equilibrium constant, #K_(eq)#, for a chemical change, we can calculate the standard state free energy change, #DeltaG^@#, for the reaction using the equation:

#Delta G^@ = -RTlnK_(eq)#

http://www.chem.purdue.edu/gchelp/howtosolveit/Thermodynamics/FreeEnergyChange.html

The equilibrium composition of the mixture is determined by #DeltaG^@# which also defines the equilibrium constant K.
http://www.chem1.com/acad/webtext/thermeq/TE5.html