Hi Ezra,

Yeah, Khan academy's coverage of solubility is rather thorough - this comes from the application of le Chatelier's and acid base chemistry, among other things, in conjunction with solubility.

If you know the basics of Ksp and are aware that these other factors can affect Ksp, knowing each topic individually well will allow you to synthesize the information on the MCAT.

I don't know when your MCAT is, but I do not think it is worth your time to slog through all of those videos - I would favor many more practice problem sets at this point.

In short, if you know:

1.What is generally soluble and what isn't (anything with first row cations tends to be soluble, and anything with NO3- as an anion tends to be soluble)
2.How to write a Ksp equation
3.Understand that Ksp is an equilibrium constant and is therefore subject to le Chatelier's

This should cover you better than most, and allow you to deal with more complex Ksp situations, should the situation arise - normally this would be introduced in a passage if it were to be more complicated.

I hope this helps!

Katt