1. Unit 8 Moles & Percent Composition Chapter 10

2. Words representing Numbers Dozen12 Baker’s Dozen13 Gross144 Ream500 Mole6.02 x 10 23

3. Avogadro’s Number 6.02 x 10 23 Number of representative particles in a mole 1 mol He = 6.02 x 10 23 atoms 1 mol H 2 = 6.02 x 10 23 molecules

4. Practice 2 mol H 2 = 12.04 x 10 23 molecules 2 mol H 2 = 24.08 x 10 23 atoms 2 mol H 2 O = 36.12 x 10 23 atoms 2 mol C 6 H 12 O 6 = 72.24 x 10 23 O atoms

5. Mole-Mass relationship 1 mole of any element equals the atomic mass in grams 1 mol Carbon = 12.01g Carbon 1 mol Iron = 55.8g Iron

6. Gram Formula Mass Mass of the formula in g/mol Simply add the atomic masses of each element in the formula together H 2 O = 1 + 1 + 16 = 18 g/mol Also known as gram atomic mass, gram molecular mass, molar mass

7. Rounding Round most masses to the nearest whole gram Except: Copper, Cu  63.5 Chlorine, Cl  35.5

8. Practice KNO 3 = 39 + 14 + 16(3) = 101 g/mol C 6 H 14 = 12(6) + 1(14) = 86 g/mol CuSO 4 = 63.5 + 32 + 16(4) = 159.5 g/mol

9. Mole - Mass Conversion Example: 96 g of Oxygen gas = ? mol

10. Practice How many moles are there in 506g of ethanol, C 2 H 6 O? What is the mass of 8 moles of CCl 4 ? 1232g CCl 4 11 mol C 2 H 6 O

11. Mole Road Map

13. Review How many moles are in 584g of SF 6 ? How many grams are in 6 mol of HCl? X = 584g 146 g/mol = 4 mol 6 mol = X 36.5 g/mol = 219 g

14. Percent Composition

15. Example H 2 O H 11.1% H O 88.9% O

16. Another Example NH 3 N 82.4% N H 17.6% H

17. Percent Composition What is the percent composition of oxygen in H 2 SO 3 ? 58.5%

18. Percent Composition What is the percent composition of aluminum in Al 2 (SO 4 ) 3 ? 15.8%

19. Percent Composition What is the percent composition of nitrogen in NH 4 NO 3 ? 35%