Thermodynamic Properties

Thermodynamic properties are defined as characteristic features of a system, capable of specifying the system’s state. Thermodynamic properties may be extensive or intensive.

• Intensive properties are properties that do not depend on the quantity of matter. Pressure and temperature are intensive properties.
• In the case of extensive properties, their values depends on the mass of the system. Volume, energy, and enthalpy are extensive properties.

What is Enthalpy?

Enthalpy is the measurement of energy in a thermodynamic system. The quantity of enthalpy equals the total heat content of a system, equivalent to the system’s internal energy plus the product of volume and pressure.

Mathematically, the enthalpy, H, equals the sum of the internal energy, E, and the product of the pressure, P, and volume, V, of the system.

H = E + PV

What is Entropy?

Entropy is a thermodynamic quantity whose value depends on the physical state or condition of a system. In other words, it is a thermodynamic function used to measure the randomness or disorder.

For example, the entropy of a solid, where the particles are not free to move, is less than the entropy of a gas, where the particles will fill the container.

Thermodynamic Potentials

Thermodynamic potentials are quantitative measures of the stored energy in a system. Potentials measure the energy changes in a system as they evolve from the initial state to the final state. Different potentials are used based on the system constraints, such as temperature and pressure.

Different forms of thermodynamic potentials along with their formula are tabulated below:

Internal Energy	�=∫���−���+∑������
Helmholtz free energy	F = U – TS
Enthalpy	H = U + PV
Gibbs Free Energy	G = U + PV – TS

Therefore, ΔG is -77kJ.