Gibbs free energy and spontaneity
At constant temperature and pressure, ΔG = ΔH − TΔS helps predict the thermodynamically favored direction of a change. ΔG < 0 indicates spontaneity under those conditions, not necessarily speed.
Core idea
At constant temperature and pressure, ΔG = ΔH − TΔS helps predict the thermodynamically favored direction of a change. ΔG < 0 indicates spontaneity under those conditions, not necessarily speed.
A concrete example
A change can be thermodynamically favorable yet extremely slow if a large kinetic barrier must be crossed.
Why it matters
This concept connects symbolic scientific language with what actually happens at atomic, molecular or experimental scales. Before applying a formula, always check the quantities, units and assumptions of the model.
Check it yourself
Restate the idea without technical vocabulary, then repeat the reasoning with a simple value. If your explanation and calculation tell different stories, revisit the assumptions.
A change can be thermodynamically favorable yet extremely slow if a large kinetic barrier must be crossed.