How is spontaneity of a change related to change in entropy and free energy ?

Free energy change is related to enthalpy and entropy changes as:

What is bond energy? How are the bond energies related to change in enthalpy of a reaction?

Statement: The thermodynamics functions which determines the spontaneity of a process is the free energy. For a process to be spontaneous, the change in free energy must be negative. Explanation:The change in free energy is related to the change in enthalpy and change in entropy. the change in entropy for a process must be always positive if it is spontaneous.

Gibbs Helmholtz equation relates the enthalpy, entropy and free energy change of the process at constant pressure and temperature as DeltaG=DeltaH-TDeltaS " (at constant P, T)" In General the magnitude of DeltaH does not change much with the change in temperature but the terms TDeltaS changes appreciably. Hence in some process spontaneity is very much dependent on temperature and such processes are generally known as entropy driven process. When CaCO_(3) is heated to a high temperature it decomposes into CaO and CO_(2) , however it is quite stable at room temperature. It can be explained by the fact that

How is free energy change related to equilibrium constant for the reaction?