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[ADAWG69]

Alright....I am doing a lad on a few laws: Boyle's, Charles' and Gay-Lussac's.
There is a question asking what would happen to the volume if the temperature (in kelvins) was decreased to 0. Technically there should still be some volume. But the Ideal Gas law (which we have not learned yet) states that at 0 the volume is 0....So somehow the volume disappears? I know at 0 kelvins motion stops but I don't see how the molecules could just disappear? I also know as temperature decreases the space between the particles decreases...so I would think they were just be super compacted...how would the matter just disappear? Anyway if anyone could help me with this that would be great!

[sk8ermike6789]

i found this:

the zero point of the ideal gas temperature scale, denoted by 0 degrees on the Kelvin and Rankine temperature scales, which is equivalent to −273.15°C and −459.67°F. For most gases there is a linear relationship between temperature and pressure (see gas laws), i.e., gases contract indefinitely as the temperature is decreased. Theoretically, at absolute zero the volume of an ideal gas would be zero and all molecular motion would cease. In actuality, all gases condense to solids or liquids well above this point. Although absolute zero cannot be reached, temperatures within a few billionths of a degree above absolute zero have been achieved in the laboratory. At such low temperatures, gases assume a nontraditional state, the Bose-Einstein condensate. See also low-temperature physics; temperature.

hope that helps a little

This post has been edited by sk8ermike6789: May 13 2004, 02:03 AM

[RevoNole]

In deep study of black holes, a black hole is infinite matter compacted in a small area, which cannot be seen or measured, with absolute zero temperature.  At absolute zero, or zero kelvin, the density of whatever substance you managed to get there would create a gravitational pull so enormous that it would collapse all matter around it.  Pretty much that would create a black hole.  Therefore, absolute zero cannot be reached unless you want to destroy everything within the gravitational vacinity.  You can also get more information on the universal working of these physics and chemistry in the book "The Elegant Universe" by Brian Greene.

This post has been edited by RevoNole: May 13 2004, 02:08 AM

[lebriznon]

ideal gas law:

PV=nRT
where P=pressure of the gas
V=volume of the gas
n=the number moles of gas present
R=the gas constant (you can look that up. it doesnt matter really)
and T= the temperature in kelvins

so rearranging the ideal gas law for V, you get V=nRT/P
and if T=0, then V=0.

thats the mathematical side of it.

[therebelious1]

the actual reason for the volume decreasing to zero lies in the definition of the ideal gas law:

ideal gas law is an ideal correllation- values predicted by it are only guestimates at best, its real usefullness is in the fact that its really easy to use and very simple

one of the main assumptions with the ideal gas law is that the molecules of the gas itself have no volume- thats why its possible to shrink the volume to zero by dropping to absolute zero

This post has been edited by therebelious1: May 13 2004, 10:44 AM

[lordvader129]

i dont bother with Boyle's, Charles' and Gay-Lussac's laws, i just use the combined law

P1 V1 / T1 = P2 V2 / T2

if the temp was dropped to 0 kelvin the function would become undefined (divide by 0) technically you can never reach 0 degrees kelvin since 0k is 0 energy, and you can never completely insulate a system to have 0 energy

[ADAWG69]

thanks a lot everyone. I could explain this using the Ideal Gas Law the only problem is our class hasn't learned it yet so I think the teacher wants us to explain in terms of the three laws I mentioned. I do know about the combined gas law, it is basically an equation to solve for the variables T1 and 2, V1 and 2, and P1 and 2 when one of those is not constant (P, V or T must be constant depending on the law you are using.) Anyway I guess I will just say it is 0 and make up some bullshit. Thanks for your help.