1. Moles and Molar Masses

2. Moles The smallest unit of matter with unique properties is an atom.
Atoms are too small to use for measurement in experiments.
6.02 x 1023 atoms = 1 mole

3. Moles con’t
The mass of 1 mole of an element can be found on the periodic table.
Atomic mass or atomic weight =# of grams in 1 mole

4. Practice Problems What is the molar mass of C?
What is the molar mass of sodium?

5. Answers Atomic mass of carbon = 12.01 1 mole C = 12.01gC
2. Atomic mass of sodium = 22.99
1 mole Na = 22.99gNa

6. Finding the Molar Mass of Compounds
The molar mass of a compound is equal to the sum of all the molar masses of the atoms in the compound.

7. Practice Problem What is the molar mass of H2O? Mass of H = 1.008g
Mass of H2 = 1.008g x 2
Mass of H2 = 2.016g
Mass of O = 16.00g
1 mole of H2O = 2.016g g
1 mole of H2O = gH2O