Thursday, December 2

Today we started off class by reviewing the 3.4 Reading Sheet. After looking over that, Mr. Henderson passed out calculators and told us how to use them more efficiently. There is a button (sto) that can store a numbers in the calculator. For example, if you wanted to store a molar mass because you would be using it in the problem a lot, you would plug that number under sto 1. So when you used that number, you would not have to type it in; you would just have to the recall 1 button. He also said that we should either be comfortable with his calculators or bring your own to use. If you bring your own calculator it cannot be an inspire.

We then went over what would the format of the test would like like.

-14 multiple choice questions

-3 pages of short answers (stoichiometry problems)

-1 question on the lab

To study for these types of problems there are review questions on the website and moodle with answers. A great way to study would be to use your packet. Everyone should have almost a completely filled out packet with correct answers. You could rework a problem that is difficult for you and check your answer with your packet. To prepare for the test in class, we completed review questions 17-19 which simulated what the questions about the lab would look like.

Furthermore, Mr. Henderson lectured us about percent yield in detail. To find the percent yield of a substance you need the theoretical yield (mass of the expected product) and the actual yield (mass of the measured product). You discover the theoretical yield by using the normal stoichiometry conversion factors, and you discover the actual yield by massing what your results are in the lab. The equation for the percent yield is:

Percent yield = Actual Yield * 100

Theoretical Yield

Lastly, we attempted problems involving this percent yield concept on a worksheet Mr. Henderson passed out. The toughest problem was number 5; the answer to it was 709.75 grams. Today was a very productive class period as we got in needed review time for the test. Finally, I would like to wish everyone good luck!