1. The Mole
Unit 3

2. Counting things… A term for a certain number of something.
Brainstorm other counting words!
Dozen =
Pair =
Gross =
A “mole” of something is x 1023 of something.
602, 000, 000, 000, 000, 000, 000, 000 12 2
144

3. The Mole
Mole: The amount of a substance that has the same number of atoms as 12 grams of the carbon-12 isotope.
Avogadro’s number: x 1023; The number of atoms in 12 grams of carbon-12.
Formula Weight is the mass in amu of 1 particle of a substance. It is numerically the same as the molar mass.
The mass of one mole of carbon-12 is 12 grams.
There are x 1023 atoms in one mole of carbon-12.

4. Particles Atoms for Elements Examples: Fe, Hg, Ne, K, C
Molecules for Covalent Compounds or Elements that exist in nature as molecules
Examples: CH4, C3H8OH, F2, SO3
Ions for Ions
Examples: Na1+, S2-, PO43-
Formula Units for Ionic Compounds
Examples: NaCl, K2SO3, Fe2O3

5. Molar Mass
The atomic weight on the periodic table is numerically the same as the molar mass.
Molar Mass: the mass of one mole of a substance.
H2O
H: 2 x 1.01 g/mol = 2.02 g/mol
O: 1 x g/mol = g/mol
2.02 g/mol g/mol = g/mol