Thermodynamics regarding ideal gases and the absolute zero.

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Discussion Overview

The discussion revolves around thermodynamics, specifically regarding ideal gases and the concept of absolute zero. Participants explore questions related to the feasibility of achieving temperatures below absolute zero, the behavior of ideal and real gases as temperature approaches absolute zero, and the significance of absolute zero as a common endpoint for both gas types.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested
  • Homework-related

Main Points Raised

  • Some participants propose that the answers to the seminar questions can be derived from a deeper understanding of molecular behavior, while others argue that statistical thermodynamics is not necessary for these questions.
  • One participant suggests looking into the canonical distribution to understand energy levels as they approach negative temperatures, questioning the implications for total energy when temperature is below zero.
  • Another participant mentions the Ideal Gas Law (pV=nRT) as a starting point for understanding the behavior of gases at low temperatures.
  • Concerns are raised about the interactions between particles at lower temperatures, which may lead to non-linear contraction in real gases compared to ideal gases.
  • One participant asserts that it is impossible to achieve absolute zero, referencing Kelvin's observations regarding the behavior of gas volume and pressure at that temperature.

Areas of Agreement / Disagreement

Participants express differing views on the necessity of statistical thermodynamics for answering the seminar questions. There is also disagreement on the implications of achieving temperatures below absolute zero and the behavior of gases as they approach absolute zero, indicating multiple competing views remain.

Contextual Notes

Some statements rely on assumptions about the behavior of gases and the interpretation of temperature scales, which may not be universally accepted or fully resolved within the discussion.

spanky489
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Hello colleagues, I have a seminar that i need to turn in a weeks day from now.
My professor listed the following questions, guidelines that I should lean on:

1) Is it possible to achieve a temperature bellow absolute zero (-273,15)

2) An ideal gas contracts linearly when decreasing temperature towards absolute zero, why?

3)A real gas doesn't contract linearly,why? it has more variables than the ideal gas, but this is not the complete answer.

4)Why is the absolute zero temperature the common ending point for both(real and ideal)

colleagues, i think the answer here lies in the specter that lies deeper than what most engineers abide by. We must go deeper than continuum, i think all the answers can be interpreted through the molecular level. And now I am asking you if you know any good links that could help me with my seminar. Also if you have any helpful information feel free to share.
 
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spanky489 said:
colleagues, i think the answer here lies in the specter that lies deeper than what most engineers abide by. We must go deeper than continuum, i think all the answers can be interpreted through the molecular level.

Nope, all these questions are answerable without making use of statistical thermodynamics (i.e. the 'molecular level').
 
alxm said:
Nope, all these questions are answerable without making use of statistical thermodynamics (i.e. the 'molecular level').

please post something constructive, a link maybe? or maybe care to elaborate on your statement.
 
Aside from the lack of evidence of sub-zero K (Kelvin) temperatures,

I think the OP should look to the canonical distribution for some information. There you could "experiment" with what would happen to the energy levels if you let them approach negative, or even zero.

You could also look to E=kT as well. Where E is total energy, k is the Boltzmann constant, and T is in Kelvin, what would happen if T < 0? Can we have a E less than zero? Can we have an E = 0?

For the second question, look to the Ideal-Gas Law.. figure it out yourself: pV=nRT

For number three, that's a fun one. I can think of a number of reasons why, depending on what level of Physics you are familiar with. I'd reckon that mentioning that interactions between particles at lower temperatures become non-negligible and so transitions between states (i.e. gas to liquid to solid) becomes important. Ideal-gas law doesn't allow for this.

4. I suggested it above I think.
 
spanky489 said:
Hello colleagues, I have a seminar that i need to turn in a weeks day from now.
My professor listed the following questions, guidelines that I should lean on:

1) Is it possible to achieve a temperature bellow absolute zero (-273,15)

2) An ideal gas contracts linearly when decreasing temperature towards absolute zero, why?

3)A real gas doesn't contract linearly,why? it has more variables than the ideal gas, but this is not the complete answer.

4)Why is the absolute zero temperature the common ending point for both(real and ideal)

colleagues, i think the answer here lies in the specter that lies deeper than what most engineers abide by. We must go deeper than continuum, i think all the answers can be interpreted through the molecular level. And now I am asking you if you know any good links that could help me with my seminar. Also if you have any helpful information feel free to share.
It is impossible to achieve absolute zero temp. Because according to the Kelvin's observations, the volume & pressure of a gas becomes zero at -273.15. i.e
temperature is inversely proportional to volume & pressure. That's why he started measuring temperature from this point.
 

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