I've read that stronger ion-dipole forces between a gaseous ion and polar water molecules cause a greater (more exothermic) hydration enthalpy. I'm struggling to make sense of this; if there is a stronger attraction between an ion and water molecules, wouldn't it be easier to dissolve the ion, since it would require less energy to bond them together because they're already attracted to each other, resulting in a less exothermic enthalpy of hydration? Specifically I am trying to figure out conceptually why CuCl2 and Cu(NO3)2 have negative enthalpies of solution. I realize that there are 2 moles of Cl- that need to be dissolved, and that increases the hydration energy significantly, but why doesn't this get "cancelled out" or overpowered by the large lattice dissociation enthalpy caused by there being a +2 charge? Thanks!