How do intermolecular forces affects solvation?

Answer 1

This can be a very complex question that you might be able to use some high end computational chemistry codes. But simply put you have van der waals forces, hydrogen bonding, and ionic bonding. You can think of it like coulumbic repulsion and attraction. hydrogen bonding has a slight negative charge on the oxygen and a slight positive charge on the hydrogen due to the covalent bond and the electron spending more time on the oxygen than the hydrogen, and the oxygens lone pair of electrons (this is inside a water molecule). Outside of the water molecule you dissolve salt nacl = na+, cl- . Since water has a slight negative charge on the oxygen, the oxygens in water molecules surround the Na+ atom pulling it into solution, and the hydrogen slight positive charge surrounds the chlorine anion. generally speaking polar groups like alcohols, ketones, amines,carboxylic acids are water soluble due to hydrogen bonding as long as there is not a large nonpolar R group. Van der waals forces control solubility on oily substances, those with large R groups like oil. since oil is a long chain of carbon it is very covalent with only very small positive and negative charges compared to water. That is why it is impossible to dissolve oil and water. Soap on the other hand has an oily R group bonded to a polar head. so one part of the molecule is polar (hydrogen bonding), and the other is non-polar and oily. A soap molecule can homogenize a solution of water and oil by being the bridge between the water molecule and the oil molecule. Hope this helps.