1. Empirical Formula The student will learn: :conceptual understanding of Empirical Formula :to calculate Empirical formula from percent :to calculate empirical formula from grams Ws.9.4

2. Which of the following is an empirical formula? C 3 H 6 O 3 C 2 H 4 N 2 O 4 CH 2 OH 2 OP 4 O 10 C 2 H 4 O 2 P 4 O 6 Hg 2 Cl 2 C 6 H 12 O 6 H 2 O 2 Al 2 O 3 Empirical Formula simplest whole number ratio for a formula

3. Empirical Formula p.229 simplest whole number ratio for a formula Steps for determining empirical formula. 1. mass of each element converted to moles. 2. divide each mole number by smallest number. Ws.9.3 1. Cholesterol: 83.39%Carbon, 11.99%Hydrogen, 4.14%Oxygen “When given % assume 100 gram sample” C 27 H 46 O

4. 2. Freon: 9.9%Carbon, 58.64%Chlorine, 31.43%Fluorine CCl 2 F 2

5. 3. 4. 5. 6. 7. 8. 9. Write answer formula for each problem

6. AP problem p. 125 The compound Adrenaline contains 56.79% C, 6.56% H, 28.37%O and 8.28%N by mass. What is the empirical formula for adrenaline?

7. The student will learn: :conceptual understanding of Empirical Formula :to calculate Empirical formula from percent :to calculate empirical formula from grams Ws.9.4

8. Molecular Formula The student will learn conceptual understanding of Molecular Formula. be able to calculate Molecular Formula.

9. Molecular Formula p.232 Empirical formula is simplest whole # ratio Molecular formula is “real world” whole# ratio X =molecular formula mass empirical formula mass X (empirical Formula) = molecular formula Given in Problem X will be a whole number

10. X = molecular mass / empirical mass x (empirical mass) = molecular formula Ws.7.4 1. CHO: experimental molar mass 116.07 2. C 2 H 4 O: experimental molar mass 88 3. C 3 H 4 O: experimental molar mass 168.19

11. 4. 5. 6. 7.

12. 4. Caffeine is a stimulant found in many drinks. Caffeine’s molar mass is 194.19g. The elemental analysis is 96.08g Carbon, 10.08g Hydrogen, 56.04g Nitrogen, 32.00g Oxygen. Calculate its molecular formula.

13. 5. The molar mass from experimentation = 392.2g. The experiment also determined the sample to be 0.70g Chromium, 0.65g Sulfur, and 1.30g Oxygen. Calculate the molecular formula.

14. 6. Propene has the simplest formula CH 2. What is the molecular formula if it has a molar mass of 42.90g/mol?

15. 7. Histamine is a substance that is released by cells in response to injury, infection, stings, which may cause allergic responses. People sometime take antihistamine drugs to counter act the effects of histamine. A sample histamine is composted of 208mgC, 31mgH, and 146mgN. The molar mass of this histamine is 111g/mol. Calculate the molecular formula for this histamine.

16. Molecular Formula The student will learn conceptual understanding of Molecular Formula. be able to calculate Molecular Formula.