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3. Putting it all together - electrostatic interactions, van der Waals interactions, H bonds and hydrophobic effect. van der Waals interaction exists between any two atoms in close contact (within the sum of their van der Waals radii). It does not have any directionality. This means that the total number of van der Waals interactions between hydrophobic molecules (e.g. hexane molecules) and water molecules, and those between the hexane molecules are perhaps quite similar. There are only van der Waals interactions between the hexane molecules. So what molecular forces drive the hydrophobic molecules such as hexane molecules to self assemble into hydrophobic core or drop in water? Explain by considering what interactions (or forces) are broken and formed in the process and the change of energy associated with the process. Also consider the second law of thermodynamics: AG < 0 for a spontaneous process, or the tendency of a system to adopt a state with the lowest energy and a change in energy occur if a force is applied to move an object over a distance. It may be help to illustrate the process using a simple diagram.