[ineedhelp]

Hey. Avogadro's hypothesis states that one mole of any gas occupies 22.4 liters at STP. What I want to know is why is the volume a constant if the number of molecules are also a constant, at the same temperature and pressure? I tried thinking about this for a while, but it seems as though I have a mental block. However, it does seem as though it is related to the kinetic energy of the individual particles, the collisions of the particles, and the attractive forces of these particles. Should I be using the Kinetic Molecular theory? I'm just sort of confused right now.

[plu]

Think about it this way: why wouldn't the volume/number of molecules/temperature/pressure stay constant?  What would cause them to change other than each other?

[Donaldson Tan]

STP = [[ 273K, 1atm ]]

At STP, real gas behaves ideally, thus we can ignore intermolecular attraction. Hence, we can consider pressure is purely the consequence of transfer of momentum from the gas molecules to the wall of the container.

If the volume of the container exceeds 22.4L, then the average distance travelled by each molecule would be longer, and thus more likely to undergo more collision. More collisions suggest the speed of each molecule will reduce while on its way to the container wall. This means there would be less transfer of momentum to the wall, thus a lower pressure than 1atm.