Equilibrium and thermodynamics are closely connected because the position of equilibrium in a chemical reaction is determined by energy changes in the system. Thermodynamics tells us whether a reaction will occur spontaneously and how far it will go before reaching equilibrium. Here’s how they are related:
- Gibbs Free Energy (ΔG):
- A reaction is spontaneous when the Gibbs free energy decreases.
- At equilibrium, the Gibbs free energy is at its minimum, and there is no net change in the system. This means the system has reached the most stable state under the given conditions.
- Entropy (ΔS) and Enthalpy (ΔH):
- Thermodynamics considers the balance between heat released or absorbed (enthalpy) and the disorder of the system (entropy).
- A reaction moves toward equilibrium in a way that balances these energy and disorder factors.
- Equilibrium constant (K):
- Thermodynamics links the equilibrium constant to the Gibbs free energy. A large equilibrium constant corresponds to a reaction that favors products, while a small one favors reactants.
- Temperature effects:
- Changes in temperature affect enthalpy and entropy contributions, which in turn shift the equilibrium position according to thermodynamic principles.