Welcome back to class!

Week 17 Resources/ Assets
Updated January 20th, 2019
Please make sure you READ everything on this page or you will miss important details. I will archive past weeks Announcements pages for a limited time only under the Trimester 1 and 2 tabs, if you need to go back to a particular weeks information for any reason.

Week 16 ​in Review

We continued this week in Chapter 9 - Stoichiometry. Please take the time to read "Calculating the Percent Yield," on pages 256 - 258 on your own. It really is a very, very easy concept. Chemists care about percent yield whenever they are performing a reaction - they want to know that their techniques were clean and tight - that they were able to recoup as much product as theoretically possible. For example, if stoichiometrical calculations from a balanced chemical equation would suggest a theoretical yield of 64.0 grams of a given product, but the chemist only acquires 23.5 grams, then the chemist might have done something wasteful or wrong. His or her percent yield would be calculated as follows:
          (23.5 grams/ 64.0 grams) x 100 = 36.7% yield

If you were baking Tollhouse Cookies, and were expected a theoretical yield of 60 cookies, but because you spilled a bunch of the mixture, or the cat ate the dough before you got it in the oven, you may only yield 41 cookies. In this case, you would calculate percent yield as:
          (41 cookies/ 60 cookies) x 100 = 68% yield

By this poor yield, you may be fired as a baker, or informed of means by which you keep the cat from eating the dough!

Upcoming Week 17
On Tuesday, we will start Chapter 10 - States of Matter. The chapter is broken down accordingly:
  • Section 10.1 The Nature of Gases
  • Section 10.2 The Nature of Liquids
  • Section 10.3 The Nature of Solids
  • Section 10.4 Changes of State
This chapter will advance what you learned earlier in the year about the three states of matter - by explaining from a thermodynamic position why a given substance of matter exists in any of these states. While this chapter is highly conceptual and not too heavy on math, don't let that fool you into thinking it is easy! Prepare yourselves to take time with the material. We will have only two class sessions at the most to cover this material! I have linked the Chapter 10 Homework at right if you want to get started.

Upcoming Test on Chapter 9
I will make the small test on Chapter 9 available by next Thursday afternoon. Since the test will cover only one chapter it will only be worth about 50 points, and due next Tuesday, January 29th.
So that  you are properly prepared for classes next week, please make sure you do the following by:
Tuesday, January 22nd:
  1. Please bring to class any questions you have from the homework.
  2. Be prepared to take the In-class Quiz #17, covering material from Chapter 9 on Limiting Reactant and Percent Yield. 

Upcoming Assignments Due
Tuesday, January 29th: 
  1. Test #4 - covering Chapter 9 only
  2. Chapter 9 Homework