1. The Mole
Mole: convenient measure of chemical quantities.
1 mole of something =  1023 of that thing.
Experimentally, 1 mole of 12C has a mass of 12 g.
Molar Mass
Molar mass: mass in grams of 1 mole of substance (units g/mol, g.mol-1).
Mass of 1 mole of 12C = 12 g.
Calculated same as molecular mass, but has different units.

4. This photograph shows one mole of solid (NaCl), liquid (H2O), and gas (N2).

5. Interconverting Masses, Moles, and Number of Particles
Molar mass: sum of the molar masses of the atoms:
molar mass of N2 = 2  (molar mass of N).
Molar masses for elements are found on the periodic table.
Formula weights are numerically equal to the molar mass.
Use Dimensional Analysis.

6. Conversions 1 mole = (molar mass) in grams
1 mole = x 1023 representative particles
1 mole = 22.4 L of a gas (at Standard Temperature and Pressure)
1 L = (molarity) in moles – for a solution.

7. GRAMS
PARTICLES
MOLES
LITERS OF GAS
LITERS OF SOLUTION

8. Examples – Make the Following Conversions:
Convert g of CO to moles.
Convert 3.60 x 1024 molecules of N2 to moles.
Convert 38.4 g of Mg(BrO3)2 to molecules.
Convert 5.03 x 1021 molecules of H2SO4 to grams.
Convert 33.9 grams of CO2 to liters (at STP).

9. Examples – Make the Following Conversions:
mol
5.98 mol
8.26 x 1022 molecules
0.819 grams L