1. Chapter 19
Avogadro’s Principle

2. Avogadro’s Principle
Avogadro's Principle states that equal volumes of gases at the same temperature and pressure contain an equal number of particles.
What is this really saying?
There are four related factors for gases, P,V,T and number of particles. If any three of these factors are equivalent then the fourth factor must be equivalent as well.

3. Avogadro’s Principle T = 0°C = 273K P = 1 atm = 101.3 kPa = 760 torr
CO2 He
T = 0°C = 273K
P = 1 atm = kPa = 760 torr
1 mol
V = ?
22.4L

4. The molar volume of a at STP.
gas
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 How many particles of H2O are in each container?
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

8. 1 mole of each at STP How many particles of H2O are in each container?
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 How many particles of H2O are in each container?
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. Why does 1 mole of all gases have the same volume at STP whereas 1 mole of solids and liquids do not?

11. Solid and liquid particles are closely packed with little space between particles.

12. 1 mole of different substances

13. Different gases can have the same volume because there is space between the particles.

14. Mole Conversions

15. What is the volume of 200.0g of H2S gas at STP?

16. What is the volume of 200.0g of H2S gas at STP?
200.0g H2S =

17. What is the volume of 200.0g of H2S gas at STP?
200.0g H2S g

18. What is the volume of 200.0g of H2S gas at STP?
200.0g H2S mol g

19. What is the volume of 200.0g of H2S gas at STP?
200.0g H2S mol
34.1g

20. What is the volume of 200.0g of H2S gas at STP?
200.0g H2S mol
34.1g

21. What is the volume of 200.0g of H2S gas at STP?
200.0g H2S mol
34.1g mol

22. What is the volume of 200.0g of H2S gas at STP?
200.0g H2S mol L
34.1g mol

23. What is the volume of 200.0g of H2S gas at STP?
200.0g H2S mol L
34.1g mol

24. What is the volume of 200.0g of H2S gas at STP?
200.0g H2S mol L =
34.1g mol

25. What is the mass of 14.7L of CO2 at STP?
28.9 grams

26. How many molecules of CO2 are in 14.7L of the gas at STP?
3.95 x 1023 molecules

27. How many atoms are in 14.7L of CO2 gas at STP?
1.19 x 1024 atoms

28. Homework
Summarize the (I) Purpose and (II) Procedure of the “Gas Laws” Lab (due tomorrow).
Study Guide Chapter 18. (due tomorrow).
Worksheet: Combined Gas Law & Graham’s Law. (due tomorrow).
Mole-Volume Conversions Worksheet (due in two days).