What is Gibbs free energy?

Sharad Jaiswal
Sharad Jaiswal

Posted On: Nov 19, 2020


Gibbs energy was given by Josiah Williard Gibbs, after which the name was given. Gibbs free energy, which is denoted by the symbol G, is equal to the addition of enthalpy and the product of temperature and entropy of the system. ΔG represents the change in Gibbs free energy. If the parameter, i.e., temperature and pressure, are constant, then the Gibbs energy equation can predict the chemical reaction's direction. It tells about the amount of energy that can be used to do work in a chemical reaction.


Where G represent the Gibbs Energy

H is enthalpy

T is temperature and

S is entropy

Gibbs free energy has the same unit as energy, i.e., joule or kilojoules.

Positive Gibbs energy: - If the Gibbs energy of a reaction is positive, it means the reaction is non-spontaneous. This reaction cannot occur by applying the external force. If the external force is stopped, then the reaction will also stop.

Negative Gibbs energy: - If the Gibbs energy of a reaction is negative, it means the reaction is spontaneous. This reaction can proceed without using any external process. All the natural reactions are spontaneous because it proceeds without external action. If the Gibbs energy is equal to zero, it means the reaction is at equilibrium.

    Related Questions

    Please Login or Register to leave a response.

    Related Questions

    Chemical Engineering Interview Questions

    What is a solvent?

    A solvent is a substance in which a solute dissolves to form a solution. The solvent can be liquid, gas, solid, or a supercritical fluid....

    Chemical Engineering Interview Questions

    What is Poly Chlorinated Biphenyls?

    PCBs or Polychlorinated Biphenyls or chlorinated hydrocarbons are a group of man-made chemicals that consist of carbon, hydrogen, and chlorine atoms. They are solid or oily liquid with yellow color an...

    Chemical Engineering Interview Questions

    What is quicklime and where it is used?

    Quicklime, also known as Calcium Oxide(CaO) or burnt lime, is a chemical compound. It is caustic, white in color, solid at room temperature. Lime refers to the organic compound containing calcium-cont...