Thomas Edison State University
General Chemistry II with Labs (CHE-122)
Semester and year: Spring 2019
Written Assignment 9: Spontaneity Reactions
Answer all assigned questions and problems, and show all work.
How does the entropy of a system change for each of the following processes?
A solid melts.
A liquid freezes.
A liquid boils.
A vapor is converted to a solid.
A vapor condenses to a liquid.
A solid sublimes.
Urea dissolves in water.
(Reference: Chang 17.5)
For each pair of substances listed here, choose the one having the larger standard entropy
value at 25ºC. The same molar amount is used in the comparison. Explain the basis for
) or CH
) – the substance can form hydrogen bonds and has a more orderly arrangement.
) or Xe(
Xe(g) – the substance has a larger molar mass therefore it has a larger standard entropy
) or CO