Particle model and pressure (3.3) (R) Flashcards
Describe the motion of gas molecules?
The molecules of a gas are in constant random motion
The temperature of the gas is related to the average (…) of the molecules
kinetic energy
Changing the temperature of a gas, held at constant volume, changes what?
the pressure exerted by the gas
Describe how increasing the temperature will make the particles hotter
If you heat something up you are giving the particles more KE and they move faster (and with more energy)
This will make the gas hotter.
Why does increased temperature cause increased pressure at constant volume?
Gases exert pressure on the container they are held it because the molecules hit the walls and bounce back in the other direction. This puts a force on the walls.
Pressure is force divided by area so there must be a pressure.
If the temperature increases then the particles are moving faster so they will hit the walls more often so the pressure will increase
What do pressure changes do to gases?
compress or expand them
What does the pressure produce at a gas container?
The pressure produces a net force at right angles to the wall of the gas container (or any surface).
Why does compressing a gas (decreasing volume) increase its pressure?
This is Boyle’s law
Because the walls of the container are now closer together so again the particles will hit them more often as they have less distance to travel and so the pressure will increase.
Why does increasing the volume decrease pressure?
If you increase the volume then the particles will have further to travel between hitting the walls so will do so less often, thus the pressure will decrease.
