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HomeworkB 06

        
(2 questions)




1)  When an ice cube (m = 23 g) melts, how much does its entropy change?  
It requires 333.9 J of heat to melt one gram of water.

  28.13 J/K
 -28.13 J/K
  1.22 J/K
 -1.22 J/K
  0.00 J/K

I basically used (333.9/273)*mass (in grams) to get the entropy change (which will be positive).

2)  What property of the H2O has changed to affect the entropy?

Disclaimer: In the real world, each property has some (usually small) effect.
We want the property that is most important in this situation.

 The molecules are moving faster-each has a bigger range of momenta available.
 The molecules are farther apart-each has a bigger range of locations available..
 The molecules rotate more- each molecule has more available orientations.

This is the answer that seemed to make the most sense to me based on this slide:

I have decided to remove the slide to respect the University's copyright on it.

Instead, see the slide here