What is the relationship between enthalpy and entropy?

1 Answer
Apr 19, 2016

Answer:

See below

Explanation:

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-TS#

where at constant temperature, the change on free energy is defined as: #Delta G=DeltaH-TDeltaS#.

Therefore, the free energy expression provides a relationship between enthalpy and entropy.

Thus, for a system at equilibrium, #DeltaG=0#, and then we find that #DeltaS=(DeltaH)/T#.