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    Absolute entropy, free energy and spontaneity

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    1) Describe in detail the difference in absolute entropy values for the following pairs:
    a) C(s, graphite) and C(s, diamond)
    b) HCl(g) and HCl(aq)
    c) CH4(g) and CH3CH2CH2CH3(g)

    2)
    a) Calculate the values of DeltaH° and DeltaS° for the following reaction at 25°C.
    b) Use the values from a to calculate DeltaG° for the following reaction at 25°C.
    c) Explain fully whether this reaction spontaneous or non-spontaneous at 25°C?

    2 CH3OH(g) + H2(g) -> C2H6(g) + 2 H2O(g) @ 25.0°C

    3)
    a) Use thermodynamics to prove that the reaction shown below is non-spontaneous at room temperature (25 °C).
    b) Calculate the temperature at which the reaction would just begin to become spontaneous.

    MgCl2(s) + H2O(l) -> MgO(s) + 2 HCl(g)

    5) Commercials make the claim that "a diamond is forever." Use thermodynamics to either prove or disprove this claim by calculating:
    a) the entropy change.
    b) the free energy change for the reaction below, and
    c) by comparing DeltaGf° for graphite and diamond.

    C(diamond) -> C(graphite)

    © BrainMass Inc. brainmass.com October 9, 2019, 6:02 pm ad1c9bdddf
    https://brainmass.com/chemistry/energetics-and-thermodynamics/absolute-entropy-free-energy-spontaneity-76435

    Solution Summary

    This solution describes the difference in absolute entropy values for 3 different

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