Question

The change in Gibbs free energy determines the direction in which a reaction proceeds. what kind of value does gibbs free energy have for the forward reaction to be spontaneous? gibbs free energy is also related to the reactions equilibrium constant. from what values can we calculate the equilibrium constant?

Answer 1

The value for an spontaneous process must be negative.

This is due to the increase of entropy in the universe... i.e

G = H-TS

and the total energy of the system (H)

if H-TS < 0

this means

H < TS

Therefore more entropy

b)

Gibbs free energy may be related to the equilibrium constant, due to the fact that when dG = 0, the system is in euqilibrium

A solved equation for an equilibrium constant is given as follow:

dGº = -RT*lnK

So temperature is defenitvely a fact for equilibrium

and the dGº of a reaction is also important.

If reaction is not in euqilibrium, use this:

G = Gº - RTlnK

in any case, you will need the change on Free energy, Temperature, and the gas constant R