I need some quick bits of info regarding solubility. How do I determine whether one substance is more or less soluble than another substance? I know to look at the solubility rules but other than that, what characteristics and properties should I be looking at? Also, how do I determine between two substances how soluble antoher substance will be? For instance, would boric acid be more soluble in ethanol or in benzene? And I know that the larger the ion, the lower the energy of hydration but what about Mg2+ and Al3+?