2. Starter
Starter analysing long answer question.docx

3. Today: Determine and use Boyle’s Law
Explain Boyle’s Law in terms of the
Kinetic Theory of Matter
Apply Boyle’s Law to problems

4. Boyle 1627-1691 A founder of modern chemistry Pioneer of the modern
scientific method
Apply Boyle’s Law
to problems
Determine and use
Boyle’s Law
Explain Boyle’s Law in terms of the
Kinetic Theory of Matter

5. Gas has three properties…
Volume
Temperature
Pressure
Apply Boyle’s Law
to problems
Determine and use
Boyle’s Law
Explain Boyle’s Law in terms of the
Kinetic Theory of Matter

6. Determining Boyle’s Law Experimentally.
Boyle was a great experimentalist.
He often avoided making hypothesis and relied solely on experimental results.
Start with a question.
How are the pressure and
volume of a gas related?
Apply Boyle’s Law
to problems
Determine and use
Boyle’s Law
Explain Boyle’s Law in terms of the
Kinetic Theory of Matter

7. Tall wide,
glass tube
Bourdon
Gauge
Oil
Reservoir
Foot Pump

8. [Pa] [cm3] Pressure Volume Determine and use
Apply Boyle’s Law
to problems
Determine and use
Boyle’s Law
Explain Boyle’s Law in terms of the
Kinetic Theory of Matter

9. Apply Boyle’s Law
to problems
Determine and use
Boyle’s Law
Explain Boyle’s Law in terms of the
Kinetic Theory of Matter

10. P∝ Boyle’s Law 1 V PV = constant
The pressure of a gas is inversely proportional
to its volume.
The pressure of a gas is directly proportional
to 1/volume. 1 P∝ V
PV = constant
Apply Boyle’s Law
to problems
Determine and use
Boyle’s Law
Explain Boyle’s Law in terms of the
Kinetic Theory of Matter

11. Assumptions Temperature remains constant Determine and use
Apply Boyle’s Law
to problems
Determine and use
Boyle’s Law
Explain Boyle’s Law in terms of the
Kinetic Theory of Matter

12. The volume of a fixed mass of gas at constant temperature is inversely proportional to the pressure.
Apply Boyle’s Law
to problems
Determine and use
Boyle’s Law
Explain Boyle’s Law in terms of the
Kinetic Theory of Matter

13. What is happening? Boyle's law simulation Determine and use
Apply Boyle’s Law
to problems
Determine and use
Boyle’s Law
Explain Boyle’s Law in terms of the
Kinetic Theory of Matter

14. What is happening?
Consider a small box of volume V1 with a gas inside at pressure P1
The gas particles are exerting a force when they bounce off the walls of the box.
Pressure is measured in N/m2
(also known as Pascals Pa)
Apply Boyle’s Law
to problems
Determine and use
Boyle’s Law
Explain Boyle’s Law in terms of the
Kinetic Theory of Matter

15. If the box shrinks? And all other variables remain constant?
There is a smaller surface area so the number of collisions per unit area increases. (P2 is greater than P1)
But V2 is smaller than V1
Apply Boyle’s Law
to problems
Determine and use
Boyle’s Law
Explain Boyle’s Law in terms of the
Kinetic Theory of Matter

16. P1V1 = P2V2
Apply Boyle’s Law
to problems
Determine and use
Boyle’s Law
Explain Boyle’s Law in terms of the
Kinetic Theory of Matter

17. Pick the correct equation and rearrange if necessary
Write out what you know
Pick the correct equation and
rearrange if necessary
Put the numbers in
Don't forget the units

18. Example Question P1V1 = P2 P1V1 = P2V2 V2 (1 x 105) x (10 x10-6) = P2
A sealed syringe contains 10 x10-6 m3 of air at 1 × 105 Pa. The plunger is pushed until the volume of trapped air is 4 x 10-6 m3. If there is no change in temperature what is the new pressure of the gas?
P1V1 = P2 V2
P1 = 1 x 105 Pa
V1 = 10 x10-6 m3
V2 = 4 x 10-6 m3
P2 = ?
P1V1 = P2V2
(1 x 105) x (10 x10-6) = P2
(4 x 10-6)
2.5 x 105 Pa= P2
Apply Boyle’s Law
to problems
Determine and use
Boyle’s Law
Explain Boyle’s Law in terms of the
Kinetic Theory of Matter

19. 2. A syringe with a radius of 4cm and 10cm long is filled with a gas at a pressure of 1.2 x 105 Pascals. The piston is pushed slowly into the syringe until the pressure on the gauge reads 1.8 x 105 Pascals. What is the new volume of gas? [5]
Apply Boyle’s Law
to problems
Determine and use
Boyle’s Law
Explain Boyle’s Law in terms of the
Kinetic Theory of Matter