PhysChemBasics#5: Chemical Equilibrium The affinity of a process has two contributions - an energetic contribution delta (H) and an entropic contribution delta (S). Temperature always increases the contribution of entropy. Sign and magnitude of delta (H) and delta (S) and temperature determine the chemical driving force delta G°. Standard Gibbs Free energy (G) ° corresponds to the difference in instability of reactants and products. From delta (G) ° we can calculate the equilibrium constant K (eq). The temperature dependence of the equilibrium constant is described by van't Hoff's equation. Qualitatively , we can discuss the shifting of equilibria with Le Chateliers principle (the principle of least constraint/stress).