<h2>A. Temperature x Entropy (TS)- The total unusable energy of a system </h2><h2>B. Free energy (G) - The total usable energy of a system</h2><h2>C. Entropy (S) - The disorder of a system</h2><h2>D. Enthalpy (H) - The total energy of a system</h2>
Explanation:
<u>The free energy</u> of the thermodynamic system is such a type of energy that is present or available to do work. So it can be called as total usable energy of the system.
<u>Entropy </u>is a thermodynamic quantity that explains about the disorder or the randomness of the system. As the temperature increases, the entropy of the system also increases.
<u>Enthalpy</u> is a thermodynamic quantity that explains the change in the internal energy so consider the total energy of the system.
