6 May 2016

What is Entropy?

Definition of Entropy :

Entropy is a thermodynamic quantity representing the unavailability of a system's thermal energy for conversion into mechanical work and interpreted as the molecular disorder in the system. 

In other words, entropy is the measure of a system's thermal energy per unit temperature that is unavailable for doing useful work. OR Entropy is also the measure of the number of possible arrangements the atoms in a system can have. 

SI unit for entropy is J / K ( joules/degree Kelvin ).

Example: 

Spraying perfume in the corner of the room and we all know what happens next. The perfume will not just stay in the corner of the room but the perfume molecule eventually fills up the room. The perfume went an ordered state to a state of the disorder so the system gets disorder so is called the higher entropy.