Speed of gas expansion & Size of expansion

In summary, two questions were asked regarding the expansion of ideal gases when heated to a certain temperature. The first question asked how quickly it would take for 100 moles of Argon heated to 373kelvins to expand to its final size. The second question inquired about the final volume and size in litres of 100 moles of Argon heated to 373kelvins. The response stated that the time it takes for the gas to expand depends on factors such as the speed of sound and the temperature. It was also mentioned that the volume of an ideal gas is proportional to its temperature, and the expansion would be greater if the gas is heated from a lower temperature.
  • #1
s.p.q.r
25
0
Hi,

Ive a couple of questions.

1) Ideal gases expand according to temperature. But how quickly does it take for it to expand to its destined size?

Lets say if I had 100 moles of Argon and heated it to 373kelvins. How long would it take for it to expand to it final size?

2) To what size will 100 moles of Argon heated to 373kelvins expand? How many litres?

Cheers gang.
 
Physics news on Phys.org
  • #2
It depends on how quickly you heat it!
And on the speed of sound in the gas, if you start heating one side of the sample the other side will only feel the heat when it has traveled through the sample - which it does at the speed of sound. To make it a little more complicated, the speed of sound in a gas depends on the temperature!

1 mole of an ideal gas is 22.4 litres at 273K (0deg C).
You don't say what temperature you started with 100l at but assuming it was 0degC the final volume = (373/273) * 22.4l/mole = 30.6 l/mole
 
  • #3
Great, let's say that the entire container was 100deg C automatically. How long would it take to reach its final expansion size?

And for the answer to the second question, i don't understand, could you clarify? Thanks.
 
  • #4
In real life it is difficult to work out, it depends on the shape of the container the initial temperature of the gas and turbulent motions of the gas.
If you heated the entire container instantly and uniformly you might not get the quickest heating of the gas as there would be no convection.
I'm not being deliberately difficult, designing heat exchangers has been a big field of study for nearly 200years, since the first steam engines.

Ideal gases always occupies 22.4L/mole at 273kelvin/1 atmosphere ( called standard temperature and pressure - STP)
As you heat the gas the expansion in volume is proportional to temperature, so if you double the temperatue you double the volume.

You don't say what temperature you started with 100moles at! If it is currently at 0deg C and you heat it to 100degC it will obviously expand more than if you are currently at 90degC and only heating it another 10deg.
 
  • #5
Sorry. Its heated to 25 degrees C.
 
  • #6
You mean heated from 25deg right?

As I said 1 mole at 273K = 22.4L
So 1 mole at 25deg C is ((273+25)/273) * 22.4
and 1 mole at 100deg C is ((273+100)/273) * 22.4
The expansion is the difference.
 

1. What is the relationship between speed of gas expansion and size of expansion?

The speed of gas expansion is directly proportional to the size of expansion. This means that as the size of expansion increases, the speed of gas expansion also increases. This relationship is known as Boyle's Law.

2. Why does the speed of gas expansion increase with size of expansion?

The speed of gas expansion increases with size of expansion because as the gas expands, the particles have more space to move around and collide with each other, causing an increase in kinetic energy and therefore, an increase in speed.

3. Can the speed of gas expansion be controlled by changing the size of expansion?

Yes, the speed of gas expansion can be controlled by changing the size of expansion. By increasing or decreasing the size of expansion, the speed of gas expansion can be controlled to a certain extent.

4. What factors can affect the speed of gas expansion?

The speed of gas expansion can be affected by several factors, including temperature, pressure, and the properties of the gas itself. Higher temperatures and lower pressures generally result in faster gas expansion, while heavier gases tend to expand at a slower rate.

5. How does the speed of gas expansion affect the behavior of gases?

The speed of gas expansion plays a crucial role in determining the behavior of gases. Faster gas expansion can lead to higher pressures and temperatures, and can also affect the rate of diffusion and effusion. It is an important factor to consider in various scientific and industrial processes involving gases.

Similar threads

Thermodynamics: gas expansion formula or approximation error?
    • Introductory Physics Homework Help
Replies
2
Views
778
Free expansion process and temperature change
    • Introductory Physics Homework Help
Replies
8
Views
1K
Minimum heat removed from gas to restore its state
    • Introductory Physics Homework Help
Replies
5
Views
2K
Deriving an expression for change in internal energy
    • Introductory Physics Homework Help
Replies
5
Views
812
Maximum temperature reached by gas in expansion
    • Introductory Physics Homework Help
Replies
27
Views
2K
B New Theory Explaining Why Certain Alloys don't change size when heated
    • Atomic and Condensed Matter
Replies
1
Views
897
I Variation of air temperature with altitude
    • Classical Physics
Replies
27
Views
883
Mixing two ideal gases with different V, T at constant pressure
    • Introductory Physics Homework Help
Replies
16
Views
2K
Can the Ideal Gas Law Adequately Explain Argon and Xenon Gas Behavior?
    • Introductory Physics Homework Help
Replies
11
Views
2K
What is the molar heat capacity of an ideal gas at constant pressure and volume?
    • Introductory Physics Homework Help
Replies
5
Views
2K

Hot Threads

Recent Insights

Back
Top