pressure

• what happens to a gas if we don't work on it?

  the temperature increases
• how can gas be compressed?

  increasing Pressure
• what is gas pressure?

  when molecules collide with the wall of their container they exert a force on the wall. the total force exerted by all the molecules inside the container on a unit of area of the wall is the gas pressure
• units of pressure?


  pascals (Pa)
• what does the equation pV = constant tell us?


  for a gas held at constant temperature, increasing the pressure will decrease the volume. vice versa
• if a gas is held at constant temp but is allowed to expand what will happen to the pressure?

  decrease