This is a non-trivial quick check. TRY THIS QUICK CHECK BEFORE WATCHING THIS VIDEO. Each step is not difficult, but there are a lot of them. Pay attention to the situation you are in at each step. Error: At 11:55 in the tutorial I make a math error. The concentration is 0.133 M, not 1.33 M, the resulting pH is 9.01, not 9.5. Oops!