What is the relationship between enthalpy and entropy ?
Enthalpy (H) is defined as the amount of
energy released or absorbed during a chemical reaction .
Entropy (S) defines the degree of randomness or disorder
in a system.
Therefore, there is no direct relationship between entropy
and enthalpy. However, the free energy (G) regroups both
terms as:
G = H - T S
where at constant temperature, the change on free energy is
defined as:
ΔG=ΔH−TΔS.
Therefore, the free energy expression provides a relationship
between enthalpy and entropy.
Thus, for a system at equilibrium, ΔG=, and then we find
that ΔS=TΔH.
