1. Moles, Molecules and Grams
A quick review!

2. National Mole Day October 23rd from 6:02 a.m. to 6:02 p.m.
Established by a high school chemistry teacher, Maurice Oehler, in 1991.
National Mole Day is celebrated around the world to engage young minds in the study of chemistry.

3. Amedeo Avogadro
6.02 x 1023

4. Things to understand about Avogadro's number
• It is a huge number, far greater in magnitude than we can visualize.
• Its practical use is limited to counting tiny things like atoms, molecules, "formula units", electrons, or photons.
• It is a number, just like a "dozen", and thus is dimensionless; you can think of Avogadro's number as the "chemist's dozen".

5. There are 12 eggs in a dozen: 12 eggs = There are 6
There are 12 eggs in a dozen: 12 eggs = There are 6.02 x 1023 molecules in a mole: =

6. Example: #12 from your worksheet
How many grams are there in 1 x 1024 molecules of BCl3?
Find the molar mass of BCl3
1 x B atom: 1 x =
3 x Cl atoms: 3 x =
g/mol

7. Example: #12 from your worksheet
How many grams are there in 1 x 1024 molecules of BCl3? 2) Set up your conversions
1 x 1024 molecules x mole x grams of BCl3
6.02 x 1023 molecules mole

8. Example: #12 from your worksheet
How many grams are there in 1 x 1024 molecules of BCl3? 3) Do your calculations and cross off your units
1 x 1024 molecules x mole x grams of BCl3
6.02 x 1023 molecules mole
= grams of BCl3

9. Conversion

10. Nomenclature
A quick review!

11. Naming Binary Compounds
A Metal and a Non-Metal....
Name of Metal + Non-Metal with suffix “ide”
Ex: CaCl
Calcium Chloride

12. Naming Binary Compounds
A Non-Metal and a Non-Metal....
(prefix) non-metal + (prefix) non-metal with suffix “ide”
Note: if the prefix of the 1st non-metal is mono,
then we do NOT write it
Ex: CO2
Carbon dioxide

13. Writing the Chemical Formula
The cross over rule.....
N O3-
N3O2