1. The Behavior of Gases
Chapter 12

3. 12.1 VARIABLES THAT DESCRIBE A GAS
PRESSURE-
TEMPERATURE-
VOLUME-
KILOPASCAL
KELVIN
LITER

5. 12.2 FACTORS AFFECTING GAS PRESSURE
AMOUNT OF GAS-(temperature is constant)
As the number of gas particles increases, the number of collisions
, therefore the pressure_______
Double the number of particles……
the pressure
INCREASE
INCREASES
DOUBLE

6. BOYLE’S LAW

7. BOYLE’S LAW
Boyle’s Law-Relation between pressure and volume
What is constant?
P1V1 = P2V2
Pressure
Volume

8. VOLUME-as volume decreases, same number of particles collide with sides of a smaller container, therefore pressure ____________
(temperature is constant)
Half the volume……..
________ the pressure
This is an ________ relationship
INVERSE
INCREASES
DOUBLE

9. GAY-LUSSAC’S LAW TEMPERATURE-PRESSURE Relationship
What variable was constant?
Pressure
Temp, K

10. INCREASES DOUBLE DIRECT
TEMPERATURE- as temperature increases, particle velocity is faster, increasing collisions, therefore
pressure ___________
(volume constant)
Double the Kelvin temperature,
__________ the pressure
This is a _________ relationship.
INCREASES
DOUBLE
DIRECT

11. CHARLES’S LAW Relationship between temperature and volume
Temperature must be in KELVIN
What is constant?
Volume
Temp, K

12. FEWER DECREASES HALF DIRECT
As the temperature of the gas inside a balloon decreases, the particle velocity is slower, making __________ collisions, and the volume of a balloon therefore ____________.
Half the Kelvin temperature, ___________
the volume.
This is a __________ relationship.
FEWER
DECREASES
HALF
DIRECT

13. WHY – 2730C 0r 0 KELVIN ?

14. 12.3 GAS LAWS COMBINED GAS LAW Combination of three prior laws
Must remember formula
Identify as having
BEFORE AND AFTER CONDITIONS

15. Ideal Gas Law
Considering all gas molecules to be the same, you can use IDEAL GAS LAW
Identity as having
only one (1) set of conditions
the number of moles (grams/MM of the gas)

16. PV = nRT Pressure kilopascals Volume liters Temperature Kelvin
n is number of MOLES
R is Universal gas constant 8.31 L kPa
mol K

17. 12.5 GAS MOLECULES
Avogadro’s hypothesis-equal volumes of gas at the same pressure and temperature contain the same number of molecules
At STP, how many molecules in 22.4 liters of
Helium, He
Hydrogen, H2

18. Dalton’s Law PT = P1 + P2 +P3 + …….
The total pressure in a gaseous system is the sum of the individual partial pressures
PT = P1 + P2 +P3 + …….
PT is total pressure of the system
P1 is pressure of gas 1, etc.

19. WHAT IS PT?

20. If a gas is collected over water, what is the pressure of just the DRY GAS?
According to Dalton,
PT= PGAS + P WATER
PGAS = PT - P WATER
WATER BATH

21. Graham’s Law of Diffusion
Gas molecules diffuse at a rate relative to size
Large molecules move slower than small molecules