What is the Difference Between Free Energy and Enthalpy?

The main difference between free energy and enthalpy lies in the work they can perform and the factors they depend on. Here are the key differences:

• Free Energy:
• Represents the total energy available to perform thermodynamic work.
• Takes into account enthalpy and entropy of a reaction.
• Can be converted to mechanical work.
• Indicates the thermodynamic favorability of a physical or chemical process.
• Enthalpy:
• Represents the total energy content in a thermodynamic system that can be converted to heat.
• Measures the amount of heat absorbed or emitted in a chemical process under constant pressure.
• Can be converted to non-mechanical work of the system.

In summary, free energy is the amount of energy available in a system to perform thermodynamic work, while enthalpy is the total energy content in a system that can be converted to heat. Free energy takes into account both enthalpy and entropy, making it a more comprehensive measure of a system's energy potential.

Comparative Table: Free Energy vs Enthalpy

The main difference between free energy and enthalpy is that free energy represents the total amount of energy available to do work, incorporating both the change in entropy (ΔS) and the change in enthalpy (ΔH) in the equation ΔG. On the other hand, enthalpy is just the change in heat of a system under constant pressure. Here is a table summarizing the differences between free energy and enthalpy:

In summary, free energy is a measure of the energy available to do work in a system, while enthalpy is a measure of the heat change in a system under constant pressure.