Ace Your AP Chemistry Journey 2025 – Unleash the Elements and Score Big!

The Gibbs free energy equation, represented as ΔG = ΔH - TΔS, is essential in thermodynamics for determining whether a process will occur spontaneously under constant temperature and pressure conditions. In this equation, ΔG represents the change in free energy, ΔH is the enthalpy change, T is the absolute temperature in Kelvin, and ΔS is the change in entropy.

When evaluating spontaneity, a negative value of ΔG indicates that the process can occur spontaneously, while a positive value suggests that it is non-spontaneous without the input of external energy. This makes the Gibbs free energy a powerful predictor of the direction of chemical reactions and physical transformations.

The relationship conveyed by the Gibbs free energy equation encapsulates both the enthalpic contributions (ΔH) and the entropic contributions (TΔS) to a process, allowing chemists to assess whether a reaction can occur naturally or if it requires energy input. The focus on spontaneous processes distinguishes this concept from others related to reaction dynamics and equilibrium.