Freienenergieunterschiede

Freienenergieunterschiede, also known as differences in free energy, are a fundamental concept in thermodynamics, particularly in chemistry and physics. The free energy, typically Gibbs free energy (G) or Helmholtz free energy (A), represents the amount of energy in a system available to do useful work. When comparing two states of a system, the difference in free energy between these states is crucial for understanding the spontaneity and equilibrium of processes.

The change in Gibbs free energy (ΔG) is defined as ΔG = ΔH - TΔS, where ΔH is the change in enthalpy (heat content), T is the absolute temperature, and ΔS is the change in entropy (disorder). A negative ΔG indicates that a process will occur spontaneously under constant temperature and pressure conditions. Conversely, a positive ΔG means the process is non-spontaneous and requires energy input to proceed. A ΔG of zero signifies that the system is at equilibrium.

Similarly, the change in Helmholtz free energy (ΔA) is defined as ΔA = ΔU - TΔS, where ΔU is the change in internal energy. ΔA is used for processes occurring at constant temperature and volume, and a negative ΔA also indicates spontaneity.

Freienenergieunterschiede are therefore used to predict the direction of chemical reactions, phase transitions, and other physical processes. For example, the difference in free energy between reactants and products determines whether a reaction will proceed to completion or reach a state of equilibrium. This concept is essential for designing chemical syntheses, understanding biological processes like protein folding, and analyzing the energy efficiency of various systems.