What is Gibbs free energy?
Gibbs free energy is a thermodynamic quantity that represents the maximum reversible work done by a system at constant temperature and pressure.
How do I calculate Gibbs free energy change?
Use the formula ΞG = ΞH – TΞS, where ΞG is the Gibbs free energy change, ΞH is the enthalpy change, T is the temperature in Kelvin, and ΞS is the entropy change.
What does a negative ΞG indicate?
A negative ΞG indicates that the reaction is spontaneous under thermodynamic conditions.
Can Gibbs free energy predict reaction spontaneity?
Yes, a negative Gibbs free energy change (ΞG) predicts that a chemical reaction will occur spontaneously at constant temperature and pressure.
What units should I use for ΞH, T, and ΞS in the formula?
Use kJ/mol for ΞH and ΞS, and Kelvin (K) for T in the Gibbs free energy calculation.
How does temperature affect Gibbs free energy?
Temperature affects Gibbs free energy through its role in the term TΞS; higher temperatures can increase the entropy contribution, potentially making endothermic reactions more spontaneous.
Is Gibbs free energy always negative for spontaneous reactions?
For a reaction to be considered spontaneous under standard conditions (25Β°C or 298 K), ΞG should be negative. However, spontaneity can depend on other factors like concentration and pressure.