Take notes on your own paper--stop, rewind, go as fast or slow as you like. Take notes as though I was lecturing in class. Write questions on the side of the paper as you go and we will answer them in class.
1) Watch video: "Determining the Mole Ratio"--5 min. You do not necessarily have to watch the entire video if you understand what is going on after the first equation is demonstrated. The second equation is repetition.
2) Watch video: "Mole Ratio Problems"--21 min. Take careful notes on this one--it is very good.
Source: YouTube--Tyler DeWitt