Free energy, also known as Gibbs free energy, is the amount of energy in a system that is available to do work. It is a measure of the energy that can be extracted from a system to perform useful work.
Chemical energy is a form of potential energy that is stored in the bonds between atoms in molecules. It is released when these bonds are broken, typically through chemical reactions, and can be harnessed to do work.
The free energy of a system is related to its chemical energy through the equation: ∆G = ∆H - T∆S, where ∆G is the change in free energy, ∆H is the change in enthalpy (heat content), T is the temperature, and ∆S is the change in entropy (disorder). This equation shows that the free energy change of a reaction is dependent on both the chemical energy change and the change in entropy.
Yes, free energy can be negative. A negative ∆G value indicates that the reaction is spontaneous and releases energy. This means that the products have less free energy than the reactants, and the excess energy is released as heat or can be harnessed to do work.
Free energy is typically measured in units of joules (J) or kilojoules (kJ). In a chemical reaction, the change in free energy (∆G) can be determined by measuring the change in enthalpy (∆H) and the change in entropy (∆S) using various techniques such as calorimetry and thermodynamics calculations.