1. Unit: Chemical Quantities
Notes
Unit: Chemical Quantities
Volume Conversions with the Mole

2. After today, you will be able to…
Calculate the volume of a gas at STP given the number of moles and vice versa
Perform two step volume conversions (Ex: atoms to liters)

3. Mole  Volume Conversions
For one mole of any gas at STP, the volume occupied will be 22.4 liters.
STP = standard temperature and pressure
= 0 degrees Celsius and 1 atmosphere
1 mole gas = 22.4 L gas

4. Example: How many moles of Helium gas will occupy a volume of 149
Example: How many moles of Helium gas will occupy a volume of 149.3L at STP?
K: 149.3L He
U: ? mol He
149.3 L He
1 mol He . x =
6.665 mol He
22.4 L He 1

5. 2-Step Conversions with Volume, Mass, and Particles
We have already learned…
How to convert moles into particles and vice versa by using the conversion factor…
1 mole = 6.02x1023 atoms, molec. or F.U.
How to convert moles into grams and vice versa by using the conversion factor…
1 mole = atomic mass in grams
How to convert moles into liters and vice versa by using the conversion factor…
1 mole = 22.4 L

6. All Roads Lead to the Mole
# of liters
1 mole = 22.4 Liters
1 mole = 6.02 x 1023 particles
MOLE
# of particles
(atoms, molecules or formula units)
1 mole = (Molar Mass) grams
# of grams

7. Example: What volume would 4
Example: What volume would 4.32x1023 atoms of Krypton gas occupy at STP?
K: 4.32x1023 atoms Kr
U: ? L Kr
4.32x1023 atoms Kr
1 mol Kr .
22.4 L Kr . x x =
6.02x1023 atoms Kr 1
1 mol Kr
16.1 L Kr

8. WS #8 : How many molecules of OF2 would have a mass of 0.132 g?
K: g OF₂
U: ? molecules OF₂
0.132 g OF₂
1 mol OF₂_ x
6.02 x 10²³ molecules. x
1 mol OF₂ . 1
g OF₂ =
1.47x1021 molecules OF2

9. WS #1 : How many moles of nitrogen gas, N2, are there in 16
WS #1 : How many moles of nitrogen gas, N2, are there in 16.8 L of this gas at STP?
K: 16.8 L N₂
U: ? mol N₂
16.8 L N₂
1 mol N₂__ x = 1
22.4 L N₂
0.750 mol N₂

10. Time to Practice! Complete WS
HOMEWORK:
Time to Practice! Complete WS

11. Complete enough problems to earn 100 points!!!