This video shows you how to do one of the most complicated types of problems you'll see in chemistry: balancing reduction oxidation equations using the ion-electron method. These problems are super tedious, and it's easy to make mistakes because there are so many steps. But on the bright side these redox problems are completely plug-and-chug, so once you get it down it's pretty difficult to get burned.
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...)