Can someone explain a PS equation?

[Scrub MD]

Avogadro's Law n/v=n/v

if a given gas has one mole of junk at a certain volume and the volume increases, will the moles also increase? I would think not but how would this equation work?

Maybe the same gas sample at diff volumes?

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[Mister Pie]

I'm pretty sure this is just derived from the ideal gas equation.

PV = nRT --rearrange--> n/V = P/RT

Provided that pressure and temperature are constant, than you get n/V = constant at a constant tempreature and pressure.

Don't interpret the equation too literally though, because it would sort of imply that if you increase V, n would increase. That makes no sense! Where would the extra molecules come from?

Instead, I think it's just important to realize that n/V = const under constant pressure and temperature. Therefore, since n1/V1 = n2/V2 = constant, and you know that n1 = n2, you know that the gases occupy the same volume.

 

[el.harpo]

Don't interpret the equation too literally though, because it would sort of imply that if you increase V, n would increase. That makes no sense! Where would the extra molecules come from?

If you're only dealing with one gas and the Pressure and Temperature are constant, then logically to increase the volume while keeping the Temp and the Pressure constant you have to increase the number of moles too .

 

[Mister Pie]

If you're only dealing with one gas and the Pressure and Temperature are constant, then logically to increase the volume while keeping the Temp and the Pressure constant you have to increase the number of moles too .

Well, that's what the equation would imply, but you can't use it in that situation if the container is sealed and you haven't added any gas yourself. The number of moles is just the number of gas molecules, so it makes no sense for you to get more molcules of gas out of nowhere just by increasing the size of the container.

On the other hand, maybe what you're saying is that for any given volume, a larger number of gas molecules should be associated with that volume (at a constant temperature/pressure). In which case I agree! The distinction I'm trying to make is for changes that the experimenter makes to the system.