What is the difference between Entropy, Enthalpy and Free Energy. I'm getting really confused and I just need someone to explain it in simple terms please.
Thanks in advance.
These are not easy to define and not easy to explain. Many people are/get confused. I looked for a good web site and found none. Basically, entropy is the degree of disorder of a system although there are some that don't like that definition. Enthalpy is the heat into or out of a system. Free energy (usually we are interested in the DIFFERENCE in free energy) is the difference between the free energy of the products minus the free energy of the reactants. If the delta G is negative the reaction is spontaneous and if the reaction is positive the reaction is not spontaneous.
Sure! I can explain it to you in simple terms.
Entropy, enthalpy, and free energy are all concepts used in thermodynamics to describe different aspects of a system. Here's a breakdown of what each of these terms means:
1. Entropy: Entropy is a measure of the disorder or randomness in a system. The higher the entropy, the more disordered the system is. It can also be thought of as a measure of the number of possible arrangements or microstates that a system can have. Entropy is denoted by the symbol "S."
2. Enthalpy: Enthalpy is a measure of the total heat energy within a system. It takes into account the internal energy of the system and the work done on or by the system. Enthalpy is denoted by the symbol "H."
3. Free Energy: Free energy is a measure of the energy available to do work in a system. It takes into account both the enthalpy and entropy of the system and is used to determine if a process or reaction is spontaneous or not. Free energy is denoted by the symbol "G."
Now, to understand the relationship between these concepts, you can consider the following:
- In a spontaneous process, the entropy of the system tends to increase (higher disorder), and the free energy of the system tends to decrease (more energy available to do work).
- Enthalpy, on the other hand, measures the total heat energy and does not directly relate to the spontaneity of a process. However, it can influence the free energy change of a system through the equation: ΔG = ΔH - TΔS, where ΔG is the change in free energy, ΔH is the change in enthalpy, T is the temperature, and ΔS is the change in entropy.
In summary, entropy measures the disorder in a system, enthalpy measures the total heat energy, and free energy measures the energy available to do work. They are related to each other through equations that describe the spontaneity of processes.