Chemistry 20 – Unit Two
Section 6 Notes:
- Introduction to the Mole
1. Mule Lab
2. Mole: A large number used by chemists to count atoms of molecules
- 6.02 x 1023 (Avogadro’s Number)
Note: mole is a number like a dozen or a million, but a large number. We are not going to
use the actual number often.
6.02 X 1023 Watermelon Seeds: Would be found inside a melon slightly larger
than the moon.
6.02 X 1023 Donut Holes: Would cover the earth and be 5 miles (8 km) deep.
6.02 X 1023 Pennies: Would make at least 7 stacks that would reach the moon.
6.02 X 1023 Grains of Sand: Would be more than all of the sand on Miami
Beach.
6.02 X 1023 Blood Cells: Would be more than the total number of blood cells
found in every human on earth.
6.02 X 1023 C02 Molecules: Would be found in 1 Mole BalloonTM at STP.
1 Liter bottle of Water contains 55.5 moles H20
5 Pound Bag of Sugar contains 6.6 moles Of C12H22O11
1 Mole BalloonTM: Contains 22.4 Liters of any gas at STP.
There are 3 types of moles that live underground in North America: Eastern
Mole, Hairy-Tailed Mole and Star-Nosed Mole
Molar Mass:
- The mass of one mole of atoms (or molecules)
Element
Cu
Fe
Al
S
O
Atomic Mass
63.5
55.8
27.0
32.1
16.0
Conversions
Number   Moles   Mass
Note: Moles = mass / molar mass
Molar Mass
63.5 g/mol
55.8 g/mol
27.0 g/mol
32.1 g/mol
16.0 g/mol
n = m/mm
Examples:
1. Convert 12.04 x 109 atoms to moles:
12.04 x 109 x 1 mole/6.02 x 1023 atoms = 2.00 x 10-14 moles
2. Convert 2.51 moles of pennies to pennies
2.51 moles of pennies x 6.02 x 1023 pennies/1 mole of pennies = 1.51 x 1024 pennies.
3. Change 3.42 moles of carbon to grams
3.42 moles of carbon x 12.0g/1mole of Carbon = 41.0g
4. Change 109.5g of Sulfur to moles
109.5g of Sulfur x 1 mole/ 32.1g of Sulfur = 3.41 moles
5. Change 27.09 x 1023 atoms of Lithium to grams
27.09 x 1023 atoms of Lithium x 1 mole/ 6.02 x 1023 atoms of Li = 4.50 moles of Li
4.50 mole x 6.02x1023 g/ 1 mole = 2.71 x 1024 g
Practice questions – converting mass to moles to atoms
Counting Atoms Assignment