Entropy is the measure of randomness. If the system is disordered, the randomness increases and consequently, entropy increases and vice versa. The entropy change for the vaporization of water is positive because the gas state has higher entropy than the liquid state.
What is Entropy?
Another form of the second law of thermodynamics states that the total entropy either increases or remains constant; it never decreases. Entropy is zero in a reversible process; it increases in an irreversible process.
Properties of Entropy
- Entropy is a thermodynamic function.
- It is a state function. It depends on the state of the system and not the path that is followed.
- It is represented by S, but in the standard state, it is represented by S°.
- Its SI unit is J/Kmol.
- Its CGS unit is cal/Kmol.
- Entropy is an extensive property which means that it scales with the size or extent of a system.