Understanding Free Energy Change
Free energy change (ΔG) is your go-to measurement for predicting whether a chemical reaction will actually happen. Think of it as the energy bookkeeper that considers everything going on during a reaction.
The clever bit is that ΔG takes into account two crucial types of energy: enthalpy change (ΔH) - the heat energy exchanged with surroundings, and the entropy change (ΔS) - how much disorder changes within the system itself.
You'll use the Gibbs equation to calculate this: ΔG = ΔH - TΔS. Remember that temperature must be in Kelvin, and watch out for units - entropy is often given in J K⁻¹ mol⁻¹, so divide by 1000 to match enthalpy's kJ mol⁻¹.
Key Rule: If ΔG is negative, your reaction is energetically feasible. Positive ΔG means it won't happen spontaneously.
