3. Mole  measurement of the number of particles in a sample  1 mol He (g) = 6.02 x 10 23 atoms  1 mol CO 2(g) = 6.02 x 10 23 molecules

4. Molar Volume  the volume of one mole of a gas at specified temperature and pressure  SATP = 24.8 L/mol  STP = 22.4 L/mol

5. Molar Volume Calculation  use the formula:

6. Molar Volume Calculation  use the formula: V=v/n

7. use the formula: Molar Volume Calculation V=v/n Molar Volume (L/mol)

8. use the formula: Molar Volume Calculation V=v/n Molar Volume (L/mol) Volume (L)

9. use the formula: Molar Volume Calculation V=v/n Molar Volume (L/mol) Volume (L) # of moles (mol)

10. Molar Volume Question What volume is occupied by 0.024 mol of carbon dioxide gas at SATP?

11. Assignment  page 169-171  Do Everything

12. Molar Mass (M)  the mass of one mole of a sample  measured in grams per mole (g/mol)  the identity of the substance DOES matter

13. Calculating Molar Mass (M)  write the correct formula  determine the number of each type of atom  multiply the number of each type of atom by the atomic mass  add up the products

14. Example  Calculate the molar mass of Ca(NO 3 ) 2(s)  M = 1 Ca + 2 N + 6 O  = (140.08) + (214.01) + (616.00)  = 164.10 g/mol

15. Mass - Mole Conversions use the molar mass of a substance to convert between mass and moles use the formula: n=m M

16. Mass - Mole Conversions use the molar mass of a substance to convert between mass and moles use the formula: n=m M # of moles (mol)

17. Mass - Mole Conversions use the molar mass of a substance to convert between mass and moles use the formula: n=m M # of moles (mol) mass (g)

18. Mass - Mole Conversions use the molar mass of a substance to convert between mass and moles use the formula: n=m M # of moles (mol) mass (g) molar mass (g/mol)

19. Example  Calculate the mass of 2.3 moles of Ca(NO 3 ) 2(s)  M = 1 Ca + 2 N + 6 O  = (140.08) + (214.01) + (616.00)  = 164.10 g/mol

20. Example  n = m/M  m= nM  m= 2.3 moles x 164.10 g/mol  m= 377.4 g