In organic chemistry, often, during the last steps of a workup we use concentrated brine solution (NaCl) to "extract" the water from the organic layer, especially when we have an organic solvent that can hold water well like diethyl ether or ethyl acetate which can hold up to 3% of their weight in water.
Brine solution "pulls" the water from the organic layer because, in doing so we obtain a more dilute solution, that has a larger volume and there is an entropy increase because even though the number of sodium and chloride ions remain the same, the whole system becomes larger and thus there are more possible microstates. Another possible explanation if the minimization of ion-ion interactions in the more dilute solutions lead to a lower energy state. Is this explanation correct or is there anything that i am missing?
- Does this mean that the dilute brine solution has a lower chemical potential than the separated solutions before the extraction?
- How is the efficiency of extraction affected by temperature? Is it correct to assume that entropy becomes a stronger driving force with the increase in temperature?
- Can we increase the efficiency of extraction by changing the type of salt we use, if so, how do I pick a better salt that "destabilizes the salt solution". For example if I were to pick an ionic compound that for example releases more ions than the normal saturated brine solution, will that be a stronger entropic driving force for the solution to dilute itself? How about if I pick a different pair of ions, how can disturb the structure of water so much that a solution would want to dilute itself even more?
