1. Mathematics of Chemistry The Mole

2. Mole = a specific Quantity like 1 dozen = 12 1. 22.4L of any gas 2. 6.02x1023 molecules 3. GFM gram formula mass H 2 O H 2 x 1 = 2 O 1 x 16 = 16 18g = 1 mole **GFM is the mass of a 1mole sample of any substance. **All base on C12 as the standard so…… H1 has a mass of 1 and = 1/12 of Carbon

3. GasAmountVolumeMoleculesMass H2H2 1 Mole O2O2 CO 2 1 Mole

4. Volume Mole Molecule Mass Volume 22.4L 6.02x10 23 GFM 6.02x10 23 ÷ X Doc’s Mole Bridge

5. What about atoms or particles? SubstanceQuantityVolume (L) (L)( MoleculesMass (grams) Atoms Or Particles Mg1 Mole22.4L6.02x10 23 24g6.02x10 23 Atoms H21 Mole22.4L6.02x10 23 2g1.02x10 24 Particles CO 2 1 Mole22.4L6.02x10 23 44g1.86x10 24 Particles X 1 X 2 X 3

6. Mass to Mole and Mole to Mass

7. Volume to Mole and Mole to Volume

9. Determine percent composition Mass of the part x 100 = % comp. Whole 1. Determine the GFM H 2 O H 2 x 1 = 2 O 1 x 16 = 16 18g part x 100 =% whole 2/18 x 100 = 11% for H 16/18 x 100 = 89% for O 100%

11. Determine the molecular (True) formula from the empirical formula and molecular mass. Empirical is NO 2 and the molecular mass is 92g 1. Determine the empirical mass NO 2 N 1 x 14 = 14 O 2 x 16 = 32 46g 2. determine how many times this goes into the molecular mass = quantity Molec Mass = quantity empirical mass 92/46 = 2 Molecular formula is N 2 O 4

12. Determine Molecular (True) Formula from Empirical Formula. The empirical formula of a compound is CH 2. Its molecular mass is 70g/mole. What is its molecular formula? A compound is found to be 40.0% Carbon, 6.7% Hydrogen and 53.5% Oxygen. Its molecular mass is 60. g/mole. What is its Molecular formula?

13. Determine the Empirical Formula from percent composition. Steps 1. Change percent to gram75% C =.75g 25% H =.25 g 2. Go from gram to mole C.75/12 =.0625 mole H.25/1 =.25 mole 3. Determine mole ratio (divide each by the lowest).0625/.0625 = 1 C.25/.0625 = 4 H Empirical Formula is CH 4

15. Percent Composition of a Hydrate 1. Same as a % comp problem 2. Hydrate is a crystal that contains water CuSO 4. 5 H 2 O This says that 1 mole of Copper II Sulfate contains 5 moles of water ****Calculate the percent of Water in the Hydrate? Steps H 2 O 1. Calculate the gfm Cu 65, S 32 and 4 Oxy 64 + 5(18) = 251 part x 100 90 x 100 = 36% Whole 251 2. Determine percent of water in Na 2 S. 9 H 2 0?

16. Stoichiometry made Simple Remember not to panic, just do ratios Piece of cake