Avogadro

1
Chapter 19

• Avogadros Principle

2
Avogadros Principle

• Avogadro's Principle states that equal volumes of
  gases at the same temperature and pressure
  contain an equal number of particles.

3
Avogadros Principle
O2
CO2
He
T 0C 273K P 1 atm 101.3 kPa 760 torr 1
mol V ?
22.4L
4
The molar volume of a gas at STP.
22.4 L
5
1 mole of each gas at STP
O2
CO2
He
How many particles of gas are in each
container? What would be the mass of each
container? What would be the volume of each
container? We now know three things about the
mole.
6
1 mole of each at STP
water
water vapor
ice
How many particles of H2O are in each
container? What would be the mass of each
container? What would be the volume of each
container?
7
The molar volume of a at STP.
gas
22.4 L
8
1 mole of each at STP
water
water vapor
ice
How many particles of H2O are in each
container? What would be the mass of each
container? What would be the volume of each
container?
9
1 mole of each at STP
water
water vapor
ice
How many particles of H2O are in each
container? What would be the mass of each
container? What would be the volume of each
container?
10
Mole Conversions
11
What is the volume of 200.0g of H2S gas at STP?
12
What is the volume of 200.0g of H2S gas at STP?
200.0g H2S

13
What is the volume of 200.0g of H2S gas at STP?
200.0g H2S
g
14
What is the volume of 200.0g of H2S gas at STP?
200.0g H2S mol
g
15
What is the volume of 200.0g of H2S gas at STP?
200.0g H2S mol
34.1g
16
What is the volume of 200.0g of H2S gas at STP?
200.0g H2S mol
34.1g
17
What is the volume of 200.0g of H2S gas at STP?
200.0g H2S mol
34.1g mol
18
What is the volume of 200.0g of H2S gas at STP?

200.0g H2S mol L
34.1g mol
19
What is the volume of 200.0g of H2S gas at STP?
200.0g H2S mol 22.4L
34.1g mol
20
What is the volume of 200.0g of H2S gas at STP?

• 131.4 L

200.0g H2S mol 22.4L

34.1g mol
21
What is the mass of 14.7L of CO2 at STP?

• 28.9 grams

22
How many molecules of CO2 are in 14.7L of the gas
at STP?

• 3.95 x 1023 molecules

23
How many atoms are in 14.7L of CO2 gas at STP?

• 1.19 x 1024 atoms

24
Homework

• Summarize the (I) Purpose and (II) Procedure of
  the Gas Laws Lab.
• Study Guide Chapter 18.
• Worksheet Combined Gas Law Grahams Law.
• Mole-Volume Conversions Worksheet (due in two
  days).