What is the difference between enthalpy and entropy?

1. Enthalpy refers to energy, and entropy refers to chaos.

2. The physical meaning of enthalpy is the energy obtained by adding the thermodynamic energy of the system to the PV energy. H=U pV. The physical meaning of entropy is the degree of chaos of the system, defined as: dS=dQ/T.

3. Qualitatively, enthalpy and entropy are both state functions, but entropy can be zero (when the number of microstates is 1) and cannot be negative (obviously the number of combinations cannot be less than 1). Extended information

Entropy S is a state function with additive (capacity) properties. It is a non-conservative quantity of extensive quantity, because the heat in its definition is proportional to the amount of matter, but a certain state has a certain quantity. The amount of change ΔS only depends on the initial state of the system and has nothing to do with whether the process is reversible or not. Since the change value of the system entropy is equal to the sum of the heat-temperature quotient δQ/T of the reversible process, the entropy change of the system can only be found through the reversible process. The reversible change of an isolated system or the adiabatic reversible change process ΔS=0.

Enthalpy is an important state parameter that characterizes the energy of a material system in thermodynamics, and is commonly represented by the symbol H. The physical meaning of enthalpy is the energy of the thermodynamic energy in the system plus the PV energy.

Enthalpy is the state function of the system and has nothing to do with the path of change. As long as the state of the system is determined, the enthalpy has a unique value.

Reference material enthalpy value_Baidu Encyclopedia