Gibbs free energy is a thermodynamic quantity that measures the amount of energy available in a system to do work. It is a combination of the system's internal energy and the energy that can be exchanged with its surroundings.
Gibbs free energy is related to enthalpy (heat content) and entropy (disorder) through the equation ΔG = ΔH - TΔS, where T is the temperature in Kelvin. This equation is known as the Gibbs-Helmholtz equation.
A negative ΔG value indicates that a chemical reaction or physical process is spontaneous and will occur without the addition of external energy. This means that the reaction is thermodynamically favorable.
The value of ΔG is affected by temperature, pressure, and the concentrations of reactants and products. It also depends on the conditions under which the reaction is taking place (e.g. constant temperature and pressure).
Gibbs free energy is an important concept in thermodynamics because it helps predict the spontaneity and direction of chemical reactions. It is also used in engineering and industry to optimize processes and determine the maximum amount of work that can be obtained from a system.