CHM 2123 Chapter Notes - Chapter 5: Sodium Acetate, Ionic Strength, Electrochemical Cell
Document Summary
However, there is one type of molecule which is so common in solutions (mostly water and all biochemical solutions) that we cannot ignore it, however, it is very ill-behaved indeed. Think about what happens when you dissolve salt (nacl) in water. The sodium and the chloride ions separate from one another giving na+ and cl-. The reason this reaction goes forward is because it results in an increase in entropy as the salt crystals dissolve. However, salt does not dissolve in many other liquids like oil. This is because in addition to an increase in entropy, there needs to be interactions between the ions and the solution that help to stabilize the ions in the soluble form. Water is very polar and can always align itself in such a way that their more positive hydrogens are pointing at the cl- and their more negative oxygens are pointing at the na+.