Explain the relation between gibbs free energy and equilibrium constant.
Answers
A spontaneous reaction has a negative delta G and a large K value. A non-spontaneous reaction has a positive delta G and a small K value. When delta G is equal to zero and K is around one, the reaction is at equilibrium. ... This relationship allows us to relate the standard free energy change to the equilibrium constant.
Gibbs free energy tells us whether a reaction is spontaneous one or not.
The change of Gibbs energy of a reaction is given by,
∆G°=∆H°-T∆S°
Where ∆G is the change in free energy, ∆H is the change in enthalpy, T is temperature in Kelvin and ∆S is change in entropy.
This equation can be rewritten in terms of free energy and reaction quotient Q.
∆G =∆G°+RT InQ
The equilibrium constant K also tells about the reaction is spontaneous are not.
At equilibrium Q=k and ∆G=0.
Then,
∆G°=-RT InK