# How does Gibbs free energy relate to work?

**Gibbs free energy**measures the useful

**work**obtainable from a thermodynamic system at a constant temperature and pressure. When a system changes from an initial state to a final state, the

**Gibbs free energy**(ΔG) equals the

**work**exchanged by the system with its surroundings, minus the

**work**of the pressure force.

Just so, what does Gibbs free energy tell us?

The **Gibbs free energy** of a system at any moment in time is defined as the enthalpy of the system minus the product of the temperature times the entropy of the system. The **Gibbs free energy** of the system is a state function because it is defined in terms of thermodynamic properties that are state functions.

One may also ask, why is Gibbs energy important? Being able to calculate the **Gibbs free energy** is **important** because you can use it to determine how likely a reaction is to occur. Negative enthalpy and positive entropy favor a reaction going forward. When it is zero, the reaction is at equilibrium.

Herein, what is the difference between Gibbs free energy and standard free energy?

**Free energy** or **Gibbs** function is by definition g = h - Ts, where h is enthalpy (J/kmol), T is absolute temperature (K) and s is entropy (J/kmol. **Standard** (or absolute) enthalpy is defined as that based on a reference wherein the value is zero for the elemental substances.

Why Gibbs free energy is negative?

Explanation: **Gibbs free energy** is a derived quantity that blends together the two great driving forces in chemical and physical processes, namely enthalpy change and entropy change. If the **free energy is negative**, we are looking at changes in enthalpy and entropy that favour the process and it occurs spontaneously.