1. Science Starter (Week 10, Friday, 4/8/16)
Grab a calculator!
When do you calculate molar mass?
What is the molar mass of NO2?
How do you tell the difference between one-step and two- step conversions problems?
What is the percent of students who passed the quiz yesterday if 12 out of 18 students passed? What about 7 out of 13 students?

2. Agenda Science Starter Percent Composition Mole Box Project
Quiz Return
Homework

3. Weekly Schedule Today: Percent Composition
Monday: 1-Step and 2-Step Stoichiometry
Tuesday: 3-Step Stoichiometry
Wednesday: Limiting Reagents
Thursday: Unit 5 Review
Friday: Unit 5 Test

4. Unit 5 Quiz: Molar Conversions
3rd Block
4th Block
Mean: 74%
Max: 100%
Min: 10%
Mean: 70%
Max: 100%
Min: 10%

5. Unit 5: The Mole Percent Composition

6. Lab: Percent Composition of Sugar in Gum Date:
Purpose: to determine the percent by mass of sugar in gum Hypothesis: Write a hypothesis about how much sugar you think is in gum. Record this, formatted as a hypothesis in complete sentences, in your hypothesis section!

7. Materials
Bubblegum
Large zip-loc bag
Scale

8. Mass of Gum and Wrappers
Recorded Data
Mass of Gum and Wrappers
Mass of wrappers
Mass of ONLY gum
Mass of Bag and Chewed Gum
Mass of Bag
Mass of ONLY chewed gum
Mass of Sugar in gum

9. Weigh all pieces of gum, still wrapped, together. Record.
Procedure
Weigh all pieces of gum, still wrapped, together. Record. 
Unwrap gum and start chewing. Wrappers must all be massed together to find gum mass. Record mass. 
Chew the gum for several minutes until you believe that all of the sugar has been dissolved in your saliva. 
Place the chewed gum in bag. Make sure it’s not all slimy! 
Mass the bag and the chewed gum. Record the mass of bag and chewed gum in your data table.

10. Mass of Gum and Wrappers
Recorded Data
Mass of Gum and Wrappers
Mass of wrappers
Mass of ONLY gum
Mass of Bag and Chewed Gum
Mass of Bag
Mass of ONLY chewed gum
Mass of Sugar in gum

11. Discussion
1) Calculate the percent sugar in your original sample of Dubble Bubble bubble gum.
2) Do you find this surprising? Why or why not?
3) Find the percent by mass of H in H2O
4) Find the percent by mass of C in C6H12O6

12. Conclusion
Write a step-by-step procedure for finding the percent by mass of a compound

13. Consensus Percent Composition
The percent by mass of each element in the compound.
Very simple calculations:
Mass of element x 100% = % by mass of element
Total mass of compound

14. Examples What is the percent by mass of oxygen in CaCO3?
What is the percent by mass of copper in Cu2S?

15. What is the percent by mass of nitrogen in Mg(NO3)2?

16. The Mole Box Project Due Friday, 4/15
Objective: to create a visual representation of THE MOLE
Directions: create a mole box that satisfies the following requirements.
Your mole box must have a theme!
Each side of the box must have the following:
Bottom = blank
Top = title
Title must be something creative involving the mole and relate to your theme
Must have a picture of a mole
Sides
1 mole = Avogadro’s Number (including #)
1 mole = molar mass
This should include 3-4 examples of your favorite elements and/or compounds with their molar mass
1 mole = 22.4 L
A mole joke or chemistry joke
Make one up!
If you can’t think of one…Google will be your best friend here
Your entire mole box should be colored/decorated in a way that has to do with your title and theme
Extra Credit: answer the following question inside your box or on a separate poster
How do we use stoichiometry in real life?

17. Quiz Return & Today’s Work