2. Review: Molar Mass of Compounds Ex. Molar mass of CaCl 2 Avg. Atomic mass of Calcium = 40.08g Avg. Atomic mass of Chlorine = 35.45g Molar Mass of calcium chloride = 40.08 g/mol Ca + (2 X 35.45) g/mol Cl  _110.98______ g/mol CaCl 2 20 Ca 40.08a 17 Cl 35.45 Cl

3. Practice Calculate the Molar Mass of calcium phosphate Formula = Ca 3 (PO 4 ) 2 Masses elements: Ca = 40.08g/mole P = 30.97 g/mole O = 16.00 g/mole Molar Mass = (40.08 g/mole)(3) + (30.97 g/mole)(2) + (16 g/mole)(8) = 310.18 g/mole

4. Mole Conversions

5. Atoms or Molecules Moles Mass (grams) Divide by 6.02 X 10 23 Multiply by 6.02 X 10 23 Multiply by atomic/molar mass from periodic table Divide by atomic/molar mass from periodic table

6. Review 5.7 kg = ?? mg

7. 3.5 dozen roses = ?? Roses 2.5 mol roses = ?? Roses (use Avogadro's #)

8. Practice Find the mass of 0.89 mol of CaCl 2. Find the molar mass of the compound: Make the conversion:

9. Practice A bottle of PbSO 4 contains 158.1 g of compound. How many moles of PbSO 4 are in the bottle?

10. molar mass Avogadro’s number Grams Moles particles/formula units/atoms Everything must go through Moles!!! Calculations

11. Practice Determine the number of atoms that are in 0.58 mol of Se.

12. Practice How many moles of barium nitrate (BaNO 3 ) contain 6.80 x 10 24 formula units?

13. molar mass Avogadro’s number Grams Moles particles/formula units/atoms Everything must go through Moles!!! Calculations

14. 2.5 g Roses = ?? Roses Atomic mass of 1 Rose is 3.0 g/mol

15. Multi-step Practice How many molecules are in 5.1g of TiO 2 ?

16. Multi-step Practice If you burned 6.10 x 10 24 molecules of ethane (C 2 H 6 ), what mass of ethane did you burn?

17. Molar Volume Definition: The volume of one mole of an ideal gas at standard conditions (STP) equal to 22.4 L. STP = standard temperature and pressure which is 0ºC and 1 atmospheric pressure 1 mole gas at STP = 22.4 L

18. Practice A container with a volume of 893L contains how many moles of air at STP?

19. Practice A chemical reaction produced 0.37 mol of N 2 gas. What volume will the gas occupy at STP?