Entropy plays a larger role in determining the Gibbs energy of reactions that take place at what?

1 Answer
Mar 17, 2018

Well, surely at higher temperature...


From the Gibbs' free energy Maxwell Relation,

#dG = -SdT + VdP#

and the enthalpy Maxwell Relation,

#dH = TdS + VdP#

We find then that

#dG = -SdT + dH - TdS#

At constant temperature, we would then get the Gibbs' isothermal relation:

#dG = dH - TdS#

Integration from the initial to the final state gives:

#int_((1))^((2)) dG = int_((1))^((2)) dH - Tint_((1))^((2)) dS#

And this should be familiar:

#=> color(blue)(DeltaG = DeltaH - TDeltaS)#

Since #DeltaS# is multiplied by the temperature, higher temperature increases the contribution of #TDeltaS# in determining #DeltaG# for a given reaction.