Why every gas would exert zero pressure at -273.15 degree celsius

In summary, when extrapolating the pressure-temperature lines on a constant volume gas thermometer, they will meet at -273.15 degrees Celsius, which is the value for absolute zero. This is not a coincidence, as the absolute temperature scale is defined based on this intersection point.
  • #1
saurabhjain
6
0
I was reading about the experiment of constant volume gas thermometer today. When we extrapolate the presuure -temperature lines, the lines would meet at point -273.15 degree celsius, which is zero presure. I was wondering whether it is a matter of coincidence or some science behind it. The lines could have intercepted at some non-zero pressure. Please help me understanding this.
 
Physics news on Phys.org
  • #2
saurabhjain said:
I was reading about the experiment of constant volume gas thermometer today. When we extrapolate the presuure -temperature lines, the lines would meet at point -273.15 degree celsius, which is zero presure. I was wondering whether it is a matter of coincidence or some science behind it. The lines could have intercepted at some non-zero pressure. Please help me understanding this.

That extrapolation is based on the assumption that the ideal gas scenario works all the way to that value. We know that this isn't true, because at some point, there will be a discontinuity in the form of a phase transition (try extrapolating the behavior of steam across 100 C).

Zz.
 
  • #3
But, still, it is no coincidence. The absolute temperature scale is defined so that intersection occurs at 0 K (absolute zero). The celcius scale is defined by the triple point of water, I believe, and that gives 0 Celcius at 273.15 Kelvin. Thus, you measure absolute zero at -273.15 C.
 

Related to Why every gas would exert zero pressure at -273.15 degree celsius

1. Why does every gas exert zero pressure at -273.15 degrees Celsius?

At -273.15 degrees Celsius, also known as absolute zero, the particles in a gas have no kinetic energy and therefore do not collide with the walls of their container. This lack of collisions means there is no pressure exerted by the gas.

2. Is there a specific reason why -273.15 degrees Celsius is the temperature at which gases exert zero pressure?

Yes, -273.15 degrees Celsius is the lowest possible temperature that can be reached, as it is the point at which all molecular motion stops. This is also known as absolute zero and is the basis for the Kelvin temperature scale.

3. Can any gas exert pressure at -273.15 degrees Celsius?

No, all gases will exert zero pressure at -273.15 degrees Celsius. This is a fundamental law of thermodynamics and cannot be changed.

4. How does the pressure of a gas change as it approaches -273.15 degrees Celsius?

As the temperature of a gas decreases, its pressure also decreases. At -273.15 degrees Celsius, the pressure will be zero, as explained by the ideal gas law.

5. Is there any way to create a gas that can exert pressure at -273.15 degrees Celsius?

No, it is not possible to create a gas that can exert pressure at -273.15 degrees Celsius. This is a fundamental law of thermodynamics and cannot be overcome.

Similar threads

  • Introductory Physics Homework Help
Replies
20
Views
4K
Replies
14
Views
2K
  • Introductory Physics Homework Help
Replies
2
Views
565
Replies
15
Views
2K
Replies
13
Views
3K
Replies
2
Views
593
Replies
1
Views
640
Replies
7
Views
885
  • Introductory Physics Homework Help
Replies
11
Views
3K
Replies
2
Views
1K
Back
Top