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Homework Help: Hydrophobic interaction with water

  1. Sep 8, 2010 #1
    1. The problem statement, all variables and given/known data
    So like lets say oil and water are interacting together. I know that they do not readily interact together and so water aggregates in a more ordered state around the oil.
    But then this is where i'm confused;
    -They say that the delta G (change in free energy) is positive, so that means free energy is required. Do they mean the energy is required to make the water molecules into a more ordered state?
    -Then they apparently the delta H (change in enthalpy) is negative, because the reaction is exothermic...like im confused...if the free energy is positive and requires free energy, wouldn't the delta H be positive indicating an endothermic reaction?


    2. Relevant equations



    3. The attempt at a solution
     
  2. jcsd
  3. Sep 11, 2010 #2

    Mapes

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    Who says that [itex]\Delta G>0[/itex] when an oil-water mixture separates? It happens spontaneously, so the Gibbs free energy must decrease.
     
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