todays lesson (supplement only) relate the change in volume of a gas to change in pressure applied...
TRANSCRIPT
Today’s lesson (Supplement only)
• Relate the change in volume of a gas to change in pressure applied to the gas at constant temperature and use the equation pV = constant at constant temperature.
Pressure in a gas
What is origin of the pressure of a gas?
Volunteers please!
Pressure in a gas
Collisions of the gas particles with the side of a container give rise to a force, which averaged of billions of collisions per second macroscopically is measured as the pressure of the gas
Pressure and Volume at constant temp?
http://phet.colorado.edu/en/simulation/gas-properties
pV = constant
• p1V1 = p2V2 (at constant temp)
This is only true for a constant mass of gas at constant temperature.
Example Question
• A packet of crisps has a volume of 200 cm3 at sea leveL (PRESSURE = 100 KPa). What volume will the packet have on the summit of Mount Everest (Pressure = 30 kPa)?
Example Question
• A packet of crisps has a volume of 200 cm3 at sea leveL (PRESSURE = 100 KPa). What volume will the packet have on the summit of Mount Everest (Pressure = 30 kPa)?
• P1 = 100 kPa, V1 = 200 cm3
• P2 = 30 kPa, V2 = ?
Example Question
• A packet of crisps has a volume of 200 cm3 at sea leveL (PRESSURE = 100 KPa). What volume will the packet have on the summit of Mount Everest (Pressure = 30 kPa)?
• P1 = 100 kPa, V1 = 200 cm3
• P2 = 30 kPa, V2 = ?
• P1 V1 = P2 V2 100x200 = 30V2
Example Question
• A packet of crisps has a volume of 200 cm3 at sea leveL (PRESSURE = 100 KPa). What volume will the packet have on the summit of Mount Everest (Pressure = 30 kPa)?
• P1 = 100 kPa, V1 = 200 cm3
• P2 = 30 kPa, V2 = ?
• P1 V1 = P2 V2 100x200 = 30V2
• 20000 = 30V2
• V2 = 20000/30 = 666 cm3
pV = constant
• p1V1 = p2V2 (at constant temp)
Can you answer the
questions that Mr Porter is giving you?
This is only true for a constant mass of gas at constant temperature.