This video covers what moles are, and how to create conversion factors for them. It also explains why your teacher is doing this "moles thing" to you, which is a question I've heard from many a frustrated chem student. Trust me, there is a reason!
Converting Grams To Moles
Lots of great grams-to-moles and moles-to-grams action in this one. Moles are confusing at first, but once you see it's always a one-step problem, it gets nice and repetitive (and that's a good thing!). Also intriguing: what to do about molecules with crazy parentheses?
Avogadro's Number (6.02 x 1023)
These mole problems get the most confusing when Avogadro's Number enters the mix: lots of scientific notation, calculators going crazy. This video will make Avogadro make sense for you, though, and it covers the common calculator mistake that's responsible for almost all of the errors students make in this type of problem.
Converting Grams to Number of Atoms or Molecules
The hardest problems are the ones going from grams all the way to number of atoms or molecules. The big trick that helps the most students involves looking at it as a basic stepping stone problem with "moles in the middle", as I'll show you in this video. Also covered: a few more advanced moles problems with funky wording to give you a taste of what's to come.
If you do not have an account, you should get one, because it is awesome! You can save a playlist for each test or each chapter, and save your "greatest hits" into a "watch right before the final" list (not that we recommend cramming, but when in Rome...)