Today

You will need a calculator! Go get it

Counting Atoms

What are some ways that we make it easier to count groups of things?

Atoms and molecules are tiny...Counting groups is a pain in the back.

18 grams of water contain 602 000 000 000 000 000 000 000 molecules (more or less...)

How can we make this easier?

1 mole = 6.023 x 1023 items

We still don’t want to count the things!

The mass of one mole is the MOLAR MASS

1 mole of iron = 602 000 000 000

000 000 000 000 atoms= 55.85 grams

Posters around the room...Lists of Elements and Compounds,

with their Molar MassI did NOT give any hint as to how I

found the molar mass.You know how to look up mass on

the periodic table for each atom.You have 5 minutes to look at the

posters and figure out what you would need to do.

Oxygen O2

32.00 grams/mole

Water H2O

18.02 grams/mole

Calcium chlorideCaCl2

110.98 grams/mole

Sodium chlorideNaCl

58.44 grams/mole

Fluorine gasF2

38.00 grams/mole

Sulfur S8

256.56 grams/mole

Baking SodaNaHCO3

56.54 grams/mole

Potassium permanganate

KMnO4

158.04 grams/mole

It seemed that...