Booth free energy, also called Gibbs function, is an important parameter in thermodynamics. It is often represented by G. Its definition is:

G = U ? TS pV = H ? TS

Where U is the internal energy of the system, T is the temperature, S is the entropy, p is the pressure, V is the volume, and H is the enthalpy.

The differential form of Gibbs free energy is:

dG = ? SdT Vdp μdn

Where μ is the chemical potential.

The physical meaning of Gibbs free energy is the maximum work that can be obtained from the system in addition to the work done by the volume change during the isothermal and isobaric process. In other words, in an isothermal and isobaric process, in addition to the work done by the volume change, the work done by the system to the outside world can only be equal to or less than the reduction in Gibbs free energy. The mathematical expression is:

If there is no work done by volume change, that is, W=0, the above formula becomes:

That is to say, before and after the isothermal and isobaric process, Gibb It is impossible for Sri Lanka's free energy to increase. If an irreversible process occurs, the reaction will always proceed in the direction of decreasing Gibbs free energy.

Specifically, Gibbs free energy is an extensive quantity, and the Gibbs free energy per unit mole of substance is the chemical potential μ

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