Free Energy

[apricimo]

Hello,

 

 

In deltaG = deltaG' +RTlnK once at equilibrium deltaG = 0

 

so

 

deltaG' = -RTlnK

 

This is supposed to be at standard temp, ph and conentration but I see it often that people will find the Keq and sub it in and get deltaG' at whatever concentration and temp, and ph they are working with for their system. That is, they are not at standard conditions. Why is this so? Is just the matter of defining your own "standard" conditions? How then do you universally say this is deltaG for this enzyme and this enzyme and be sure that their conditions are the same?