1. Gas

2. Kinetic Molecular Theory
the tiny particles in all forms of matter are in constant motion

3. What is a gas?

4. Gas Elements

5. Properties of Gasses (determines why a gas behaves the way it does)
Pressure
Volume
Amount
Temperature

6. Pressure
the force a gas exerts on the inside walls of its container

7. Pressure
Measured in atmospheres (atm), pascals (Pa), millimeters Mercury (mmHg)

8. Volume
the space of the container it is trapped in

9. Volume
Measured in m³ or Liters

10. Amount
amount of gas molecules in a given sample

11. Amount
Measured in moles
Convert mass to moles by dividing by molar mass

12. measured in units called Kelvin
Temperature
measured in units called Kelvin
Useful in measuring very cold temperatures

13. Temperature Convert C to K by adding 273
The Kelvin scale starts at Absolute 0, which is -273°C.

14. Kelvin Practice Absolute zero is 0 K or -273°C
Calculate the missing temperatures:
0°C = _____ K 100°C = _____ K
100 K = _____ °C -30°C = _____ K
300 K = _____ °C 400 K = _____°C
25 °C = _____ K 0 K = _____°C

15. The Gas Laws
For a fixed amount of gas, a change in one variable (pressure, temperature, or volume) affects the other two

16. the relationship between pressure and volume of a gas
Boyle’s Law
the relationship between pressure and volume of a gas

17. What does this mean?

18. the volume of a gas is inversely proportional to its pressure
Boyle’s Law
the volume of a gas is inversely proportional to its pressure
Irish Chemist
Robert Boyle
( )

19. Inversely Proportional
when one goes up, the other goes down
pressure
volume

20. Boyles law at work…

21. Constants
Amount and temperature

22. Equation:
P₁V₁ = P₂V₂

23. Boyle’s Law Illustrated

24. Boyle’s Law
A gas has a volume of 3.0 L at 2 atm. What is the volume at 4 atm?
3.0 L x 2 atm = P₂ x 4 atm

25. PV = k Boyle’s Law Volume Pressure P.V P V 10.0 20.0 30.0 40.0 760.0
(mL)
Pressure
(mmHg)
P.V
10.0
20.0
30.0
40.0
760.0
7600
380.0
7600
253.3
7600
190.0
7600 P V
PV = k

26. PV Calculation (Boyle’s Law)
A quantity of gas has a volume of 120 dm3 when confined under a pressure of 93.3 kPa at a temperature of 20 oC. At what pressure will the volume of the gas be 30 dm3 at 20 oC?
P1 x V1 = P2 x V2
(93.3 kPa) x (120 dm3) = (P2) x (30 dm3)
P2 = kPa