CBSE Class 12-science Answered

The Gibbs free energy of a system at any moment in time is defined as the enthalpy of the system minus the product of the temperature times the entropy of the system. The Gibbs free energy of the system is a state function because it is defined in terms of thermodynamic properties that are state functions. The change in the Gibbs free energy of the system that occurs during a reaction is therefore equal to the change in the enthalpy of the system minus the change in the product of the temperature times the entropy of the system. G = H - (TS).Gibbs free energy is used to determine if a reaction will proceed spontaneously in the forward direction. If the sign is negative, the reaction should proceed spontaneously; if the sign is positive it will not. If the sign is 0 the reaction is at equilibrium and the rate of the forward reaction will equal the rate of the reverse reaction.