Why Is the Delta G Positive in Hydrophobic Interaction with Water?

AI Thread Summary
In hydrophobic interactions, the positive delta G indicates that free energy is required for the system to reach a more ordered state, as water molecules form structured arrangements around oil. This ordering occurs despite the negative delta H, which suggests that the process is exothermic and releases heat. The confusion arises from the relationship between delta G and delta H, where a positive delta G does not necessarily imply that the reaction is endothermic. Instead, the overall process can be spontaneous due to the increase in entropy associated with the separation of oil and water. Understanding these thermodynamic principles clarifies why oil and water do not mix readily.
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Homework Statement


So like let's 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 I am confused...if the free energy is positive and requires free energy, wouldn't the delta H be positive indicating an endothermic reaction?


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