Question

Free energy change of reversible reaction at equilibrium is

Answer 1

is also free energy is right

Answer 2

Gibbs energy or Gibbs function ( G ) is a thermodynamic function that can be defined as



G is an extensive property and a state function.
The change in Gibbs energy for the system ΔG sys, is given by


At constant T, ΔT = 0



ΔG has the units of energy (KJmol-1).
ΔG is related to reaction spontaneity. It gives the criteria for spontaneity at constant pressure and temperature.
For spontaneous process,

∴− ΔG > 0

Or, ΔG = ΔH − TΔS < 0

If ΔG < 0 (i.e., negative), the process is spontaneous.
If ΔG > 0 (i.e., positive), the process is non-spontaneous.
When a reaction has a positive enthalpy change and positive entropy change, it can be spontaneous if TΔS is large enough to outweigh ΔH.