Pressure Laws

Question 1

As the volume of a gas increases, what happens to the pressure ?

Answer 1

the pressure will decrease
- the particles now have more space to move
- this means less collisions with the walls of the container and less internal energy
- therefore less pressure on walls of container

Question 2

If the volume of a gas decreases and the temperature is increased what happens to the pressure ?

Answer 2

• volume decreased means less space for the particles to move
• this means more collisions with walls of container
• increasing temperature increases kinetic energy of particles and therefore internal energy
• leads to more forceful and frequent collisions

Question 3

What is the formula for constant ?

Answer 3

pV = constant

Question 4

A gas has a volume of 2 metres cubed and a pressure of 400,000 Pa. The volume is increased to 6 metres cubed. What is the pressure ?

Answer 4

2 * 400, 000 = 6 * p
800, 000 = 6 * p
p = 133, 333 Pa

Question 5

Why does the temperature of a bicycle pump increase after a short period of time ?

Answer 5

• This is because when we press down on the pump, we do work.
• This means that energy is transferred to the gas particles, in the form of internal energy
• internal energy includes kinetic AND potential energy
• as kinetic energy increases, so does the temperature as there are more collisions talking place