1. Empirical and Molecular Formulas

2. Create a Placemat on Your Giant Whiteboard…
Drill
Create a Placemat on Your Giant Whiteboard…

3. What is the percent composition of Bromine in CuBr2?
Drill
What is the percent composition of Bromine in CuBr2?

4. Agenda Drill Review of HW Empirical/Molecular Formula Notes
Case of the Chemical Culprit
Extra Practice (HW if not finished in class)
Looking Forward
CHECK FOR UNDERSTANDING ON PERCENT COMPOSITION AND EMPIRICAL FORMULA NEXT CLASS!!!!

5. Case of the Chemical Culprit
Ms. Fair’s room was left a mess the other day and found a mysterious substance on her desk. After watching the school’s cameras, she saw that there were 5 possible subjects and she examined their hands and found different substances on them.
She determined the mystery substance, but did not have time to determine what the substances were on the suspects.

6. Your Task
Use your notes to determine the empirical formula for the 5 different suspects
After calculating all results, see Ms. Fair’s results in the front of the room to determine who the culprit was!

7. HW
If you did not finish the additional practice, complete that for HW!!! 

8. Check for Understanding on Empirical Formula and Percent Composition
Looking Forward
Check for Understanding on Empirical Formula and Percent Composition
Possible Lab – Have to try it first

9. Empirical Formula The lowest whole number ratio of atoms in a compound
Formulas for ionic compounds are ALWAYS empirical (lowest whole number ratio)
Examples:
NaCl
Al2(SO4)3
MgCl2

10. Molecular Formula
The true number of atoms of each element in the formula of a compound
Example:
C2H8
P4O10

11. Molecular and Empirical Formulas
Formulas for molecular compounds MIGHT be empirical (lowest whole number ratio)
Molecular
Empirical
H2O
C6H12O6
CH2O
C12H22O11

12. Which of the following is NOT an empirical formula?
Na2SO4
C6H5Cl
N2H4
Sn3(PO4)4

13. Check for Understanding
The lowest whole-number ratio of the elements in a compound is called?
Empirical formula
Molecular formula
Binary formula
Representative formula

14. Check for Understanding
Which of the following compounds have the same empirical formula?
CO2 and SO2
C7H14 and C10H20
C4H10 and C10H4
C6H12 and C5H14

15. Check for Understanding
Which of the following is NOT true about empirical and molecular formulas?
The molecular formula of a compound can be the same as its empirical formula.
The molecular formula of a compound can be the same whole- number multiple of its empirical formula.
Several compounds can have the same empirical formula, but have different molecular formulas.
The empirical formula of a compound can be triple its molecular formula