Question

During winters, moisture condenses in the form of dew and can be seen on plant leaves and grass. The entropy of the system in such cases decreases as liquids possess a lower disorder as compared to gases. With reference to the second law, which statement is correct, for the above process?

• A. The randomness of the universe decreases
• B. The randomness of the surrounding decreases
• C. Increase in randomness of surroundings equals the decreases in randomness of system
• D. The increase in randomness of the surrounding is greater as compared to the decrease in randomness of the system.

Answer 1

The correct option is D The increase in randomness of the surrounding is greater as compared to the decrease in randomness of the system.

As Dew formation is spontaneous process So
$\Delta S_{universe}\ge 0$
$\Delta S_{universe}=\Delta S_{syt}+\Delta S_{surrounding}\left(1\right)$

Condensation of moisture means heat is released So $\Delta S_{sytm}=\frac{-q}{T}$ is decreasing .
$\Delta S_{universe}=\Delta S_{syt}+\Delta S_{surrounding}$
$\frac{-q}{T}+\Delta S_{surrounding}\ge 0$
$\Delta S_{surrounding}\ge \frac{q}{T}$
The increase in randomness of the surrounding is greater as compared to the decrease in randomness of the system.