Question

A student attempted to dissolve a liquid ionic solute in a nonpolar solvent. The resulting mixture showed three distinct layers...?

This would be classified as...

a) chemical change because the ionic solute and the nonpolar solvent did not mix

b) physical change because the ionic solute and nonpolar solvent did not mix

c) chemical change because 3 distinct layers were formed

d) physical change because 3 distinct layers were formed

The answer is C but I'm not sure why.

Answer 1

Well, if no chemical change happened, wouldn't you expect 2 distinct layers? That is, if two things were poured into one container and then naturally separated with no reaction, wouldn't you expect 2 layers only?

If there were only 2 distinct layers, then `(b)` would be correct, because you have two substances that didn't mix. You don't have three substances to begin with, so something chemical must have happened that generated a third phase.