Chemical Thermodynamics Question 4

Question: The enthalpy change for the transition of liquid water to steam, $ \Delta H_{vap}=37.3 kJ mo{{l}^{-1}} $ at $ 373 K $ . The entropy change for the process is [MP PET 1994]

Options:

A) $ 111.9 J mo{{l}^{-1}}{{K}^{-1}} $

B) $ 37.3 J mo{{l}^{-1}} {{K}^{-1}} $

C) $ 100 J mo{{l}^{-1}}{{K}^{-1}} $

D) $ 74.6 J mo{{l}^{-1}}{{K}^{-1}} $

Show Answer

Answer:

Correct Answer: C

Solution:

$ \Delta S_{vap}=\frac{\Delta H_{vap}}{T}=\frac{37.3 KJ mo{{l}^{-1}}}{373K} $

$ =0.1 kJ mo{{l}^{-1}} {{K}^{-1}} $

$ =100J mo{{l}^{-1}} {{K}^{-1}} $ .