I had a strange experience today. I was teaching partition coefficients to my A2 class today. Put simply, if you have 2 immiscible liquids, some of the chemicals dissolved in one will dissolve in the other if you mix them. Partition coefficients tell you how much of the chemical is dissolved in each of the solvent.

Anyway there's a trick with the 2 solvents. If you add 20mls of one solvent to the other, a certain amount of the chemical will be transferred to the new solvent. However, if you add 2 lots of 10mls (one after another), more of the chemical will be transferred. Weird huh?

Anyhow, I was teaching this to class and when I explained this, I got a gasp out of the class, when they got it. It really cheers me up when this sort of thing happens.