Chem133 Chapter20

  1. When is a reaction spontaneous?
    when it proceeds under the specified conditions.
  2. What is the entropy of a system?
    What are its units?
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    • k = R/avagadro's
    • W= number of microstates
    • J/°K
  3. What is the change of entropy in a system when heat is added?
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  4. What is standard molar entropy?
    • Because entropy depends on amount of substance we define it to have units of J mol-1 K-1
  5. Calculate the standard entropy of a reaction
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    • Where m and n are moles of products and reactants
  6. Calculate the ⌂Ssurr
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    • At constant pressure:
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  7. Calculate the free energy of a system.
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  8. Calculate the ⌂Gsys
    What can it tell us?
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    • ⌂G<0: Spontaneous
    • ⌂G=0: Equilibrium
    • ⌂G>0: Nonspontaneous
    • How much work can be done by (or needs to be done to) a system
  9. What is another way to calculate ⌂G?
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Card Set
Chem133 Chapter20