If I mix water with methanol I get a single phase, but when i mix methanol with hexane I get two phases, this happens because methanol is soluble in water but not in hexane. How can I explain the solubility of a substance in terms of energy and intermolecular forces involved?

Question

jfraser · Answer

Can you draw the lewis structures of methanol, water, and hexane? That's the first step in figuring out what IMFs are involved

tatianagomezb · Answer

Yes, I can do that. I know methanol and water have similar structures and inter. forces. And that hexane as a chain only has dispersion forces, which is why methanol isn't soluble in it. However I don't understand how to explain the energy variation in both cases. 
$$\Delta G mix= \Delta H \times T \Delta S$$
If the entropy is favorable because is a mix how is enthalpy related to it. Thanks for the reply