Question

What is the entropy change (in${JK}^{-1}{mol}^{-1}$) when one mole of ice is converted into water at $0^{o}C$?

• A. 20.13
• B. 2.013
• C. 2.198
• D. 21.98

Answer 1

The correct option is D 21.98

The heat of fusion for water at $0^{o}C$ is approximately $334$ joules (79.7 calories) per gram.

So for 1 mole of Water enthalpy of fusion $=334\times 18\approx 6000Jmo{l}^{-1}$

$\Delta S=\frac{q_{rev}}{T}=\frac{6000}{273}=21.978J{K}^{-1}mo{l}^{-1}$

So the entropy change is $21.98$
Ice is converted into the water so entropy change will always be positive.

Option D is the correct answer.