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Homework Help: Chemistry Extra Credit Prob.

  1. May 10, 2007 #1
    Hi again,

    Need help with one more question if anyone don't mind. Any help is appreciated. Thanks in advance.

    Arrange these three processes in order of their decreasing tendencies toward spontaneity.

    I. H2O (l) --> H2O (g) at 105 C degrees, 1.00 atm
    II. H2O (l) --> H2O (s) at 25 C degrees, 1.00 atm
    III. H2O (l) --> H2O (s) at 0 C degrees, 1.00 atm

    Select one answer
    a) I > III > II
    b) II > III > I
    c) I > II > III
    d) III > II > I
    e) II > I > III

    I think the answer is (a) because the gas form is more sponteous than the solids. And then its the third one then the second one because the temp. of 3rd one is less than 2nd. ??
    Last edited: May 10, 2007
  2. jcsd
  3. May 10, 2007 #2


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    Homework Helper

    Which answer do you think it is? You need to show some effort, you know!
  4. May 10, 2007 #3
    Sorry. Ok I've given my opinion for this question. Let me know if im wrong or right.
  5. May 11, 2007 #4
    Take a look at the Gibbs Free Energy Equation:
    ΔG = ΔH - TΔS(init)
    whereas T is the temperature (SI Units: kelvins); S is the entropy (SI Units: joules per kelvin); H is the enthalpy (SI Units: joules)

    and remember that when ΔG < 0 the reaction is spontaneous...
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