Relationship between free Energy and Equilibrium Constant

The free energy change of the reaction in any state, ΔG (when equilibrium has not been attained) is related to the standard free energy change of the reaction, ΔG0 (which is equal to the difference in free energies of formation of the products and reactants both in their standard states) according to the equation.

      ΔG = ΔGo + RT InQ

Where Q is the reaction quotient

When equilibrium is attained, there is no further free energy change i.e. ΔG = 0 and Q becomes equal to equilibrium constant. Hence the above equation becomes.

           ΔGo = –RT In K(eq) 

      or  ΔGo = –2.303 RT log K(eq)

In case of galvanic cells. Gibbs energy change ΔG is related to the electrical work done by the cell.

ΔG = -nFE(cell) where n = no. of moles of electrons involved

                        F = the Faraday constant

                        E = emf of the cell

If reactants and products are in their standard states ΔGo = –nFEocell

Solved example: Calculate ΔG0 for conversion of oxygen to ozone 3/2 O2 (g) ——> O3 (g) at 298 K, if Kp for this conversion is 2.47 ´ 10-29.

Solution: ΔGo = –2.303 RT log Kp

Where R = 8.314 J/K mol, Kp = 2.47 ´ 10-29, T = 298K

       ΔG0 = 16300 J/mol = 163 KJ/mol.

To know more about the study material of engineering and medical exams, please fill up the form given below:

We promise that your information will be our little secret. To know more please see our Privacy Policy
We promise that your information will be our little secret. To know more please see our Privacy Policy

OR

Sign Up with Facebook

Signing up with Facebook allows you to connect with friends and classmates already using askIItians. It’s an easier way as well. “Relax, we won’t flood your facebook news feed!”

Related Resources
Third Law of Thermodynamics

THIRD LAW OF THERMODYNAMICS:- In all heat engines,...

Level 1 Objective Problems Of Thermodynamics

Solved Examples on Thermodynamics:- Problem 1 :- A...

Enthalpy of Reaction

Enthalpy of Reaction It is the enthalpy change...

Enthalpy of System

Enthalpy of a System The quantity U + PV is known...

Heat Capacity and Specific Heat

Specific Heat Capacity or Specific Heat [c]:- It...

Thermodynamic Process and their Types

Thermodynamic change or Thermodynamic Process:-...

HESS Law

HESS’S LAW This law states that the amount...

Level 2 Objective Problems Of Thermodynamics

Level 2 Objective Problems of Thermodynamics Level...

Application of Bond Energies

Application of bond energies (i) Determination of...

Work done during isothermal expansion

Work Done During Isothermal Expansion:- Consider...

GIBBS Free Energy

Gibbs Free Energy This is another thermodynamic...

Introduction to Thermodynamics

Introduction to Thermodynamics:- Thermodynamics:-...

Application of Hess Law

Application of Hess's Law 1. Calculation of...

First Law of Thermodynamics

The First Law of Thermodynamics:- The first law of...

Objective Questions of Thermodynamics

Objective Questions of Thermodynamics and Answers...

Work done during adiabatic expansion

Work Done During Adiabatic Expansion:- Consider...

Macroscopic Extensive Intensive Properties

Macroscopic Properties He properties associated...

Solved Problems Part 1

Solved Problems on Specific Heat, Latent Heat and...

Solved Sample Problems Based on Thermodynamics

Solved Problems on Thermodynamics:- Problem 1:- A...

State of System

Thermodynamic State of a System and Macroscopic...

Second Law of Thermodynamics

Second Law of Thermodynamics:- Entropy:- The...

Specific Heat Capacity and Its Relation with Energy

Specific Heat Capacity and Its Relation with...

Reversible Irreversible Process

Reversible and Irreversible Process:- Reversible...

Miscellaneous Exercises Part I

Miscellaneous Exercises Thermal Physics:- Problem...

Bomb Calorimeter

BOMB CALORIMETER The bomb calorimeter used for...