1. Mr. Quinn & Ms. TomJanuary 14, 2014 Aim: How can we solve empirical formulas where the smallest coefficient is not the greatest common factor? Do Now: What is the greatest common factor of both 10 and 15? Find the smallest whole-number ratio: 9:6:81

2. Solve the Empirical Formula: C 8 H 16

3. Solve the Empirical Formula:

4. Al 4 O 6

5. Mass data of Aluminum Oxide Al: 53 % O: 47 % Solution: If you come up with a 0.5 or similar, multiply by 2 to get back to a whole number

6. Checking in! What is the empirical formula of a compound that has a carbon-to-hydrogen ratio of 2 to 6? 1.CH 3 2.C 2 H 6 3.C 3 H 4.C 6 H 2

7. Calculate the formula of barium oxide: B: 31 % O: 69 %

8. Calculate the empirical formula of this molecule:

9. Calculate the formula of formaldehyde: C: 42.2 % H: 6.8 % O: 51 %

10. Checking in! Given two formulas representing the same compound: Formula A: CH 3 Formula B: C 2 H 6 Which statement describes these formulas? 1.Formulas A and B are both empirical. 2.Formulas A and B are both molecular. 3.Formula A is empirical, and formula B is molecular. 4.Formula A is molecular, and formula B is empirical.

11. Your Turn!

12. Exit Ticket Your calculations lead you to determine that the mole ratio of Cs to O in cesium oxide is 2:1. What is the formula for cesium oxide? 1.CsO 2.CsO 2 3.Cs 2 O 4.Cs 2 O 2