2002 AIPMT ThermodynamicsEntropy Easy Question 3 of 3 in Entropy

Unit of entropy is : -

A J K$^{-1}$ mol$^{-1}$
B J mol$^{-1}$
C J$^{-1}$ K$^{-1}$ mol$^{-1}$
D J K mol$^{-1}$

The answer is A.

Solution

Entropy change: $\Delta S = \dfrac{q_{rev}}{T}$, so the unit of entropy is energy/temperature, i.e. J K$^{-1}$.
Molar entropy is expressed per mole: J K$^{-1}$ mol$^{-1}$.
So the unit of entropy is J K$^{-1}$ mol$^{-1}$.

Concept Unit of entropy

Entropy in past papers

3 questions from this chapter have appeared across 3 exam years.