Name: _______________
Connecting States to Entropy
PART I The cubes represent particles (atoms, molecules, ions, etc.) that have enough attraction to resist separation because of thermal motion. The particles therefore “want” maximum contact with each other. Arrange the particles into the most likely arrangement. Explain how and why you organized your cubes the way you did. Draw a picture of your cubes.
How many configurations can this model be made into? How does that relate to entropy? What state do your cubes represent? PART II Now there is enough thermal vibration for the cubes to move around but not completely break apart. Every cube has to share at least one face with every other cube. Explain how and why you organized your cubes the way you did. Draw a picture of your cubes.
How many configurations can this model be made into? How does that relate to entropy? What state do your cubes represent? PART III Follow what you know about the kinetic molecular theory. You may move the cubes independently from each other, average separation >10 cm, while moving them in straight lines until they bounce off each other or other things (this can’t be done too realistically!). Explain how and why you organized your cubes the way you did. Draw a picture of your cubes.
How many configurations can this model be made into? How does that relate to entropy? What state do your cubes represent?
American Association of Chemistry Teachers
1
Analysis 1. If you had more blocks, what would happen to the number of possible configurations? How does that relate to the entropy of the system? (Note: The term microstates is sometimes used instead of configurations.)
2. Which has more entropy … … one mole of gas or two moles of gas? Explain.
… one mole of liquid or one mole of gas? Explain.
3. a. If water is synthesized and all three components are gases at the same temperature, is there more entropy in the reactants (hydrogen and oxygen) or the product (water molecules)? Write out the balanced chemical equation, including states, and explain.
b. Does your answer change if the water that is synthesized is in the liquid state? Explain.
American Association of Chemistry Teachers
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