Quick question about perfect gas

In summary, the conversation discusses two different gases, Helium and Cripton, being mixed together. The question is raised about which property of a perfect gas is important for this mixture to behave as a perfect gas. The topic of mass is ruled out, as it cannot have equal values in any circumstances. The possibility of equal kinetic energy due to the gases being at the same temperature is also considered, but it is not a guarantee for every type of mixture. The concept of thermal equilibrium is mentioned as a property that would result in equal kinetic energy, but it may not always apply. The conversation ends with a question about other properties that could help determine if the mixture is a perfect gas.
  • #1
criticalPoint
3
0
New user has been reminded to use the Homework Help Template and show their work in the first post
Two different gasses (Helium and Cripton) are mixed up. We can assume the compound behaves as a perfect gas only if the atoms of He and Kr have the same average value of:
  • Mass
  • Momentum
  • Velocity
  • Kinetic energy
Which one is correct? I can't figure it out.
 
Physics news on Phys.org
  • #2
Which one do you think it is and why? Let's start there.
 
  • #3
Obviously it's not mass (average mass can't be equal in any circumnstances), because they are at the same temperature I suppose they have the same kinetic energy, but wouldn't that happen for every kind of mixture? I can't undestand what specific property of a perfect gas is important here, what makes this mixture perfect and not real.
 
  • #4
criticalPoint said:
Obviously it's not mass (average mass can't be equal in any circumnstances)
I agree about mass.
criticalPoint said:
because they are at the same temperature I suppose they have the same kinetic energy, but wouldn't that happen for every kind of mixture? I can't undestand what specific property of a perfect gas is important here, what makes this mixture perfect and not real.
Not necessarily. Maybe after a long period of time every mixture will be in thermal equilibrium, but it doesn't have to be the case. I agree thermal equilibrium is a property which would imply the same kinetic energy. What are the other properties? Can they help us here?
 

1. What is a perfect gas?

A perfect gas is a theoretical gas that follows the kinetic theory of gases. It is assumed to have no intermolecular forces and its molecules are considered to have negligible volume. This means that the particles in a perfect gas are constantly in random motion and collide elastically with each other and the walls of the container.

2. How is a perfect gas different from a real gas?

A real gas does not follow the assumptions of a perfect gas, as it does have intermolecular forces and its molecules do have a finite volume. This means that the behavior and properties of a real gas can deviate from those of a perfect gas, especially at high pressures and low temperatures.

3. What are the properties of a perfect gas?

A perfect gas is characterized by its pressure, volume, temperature, and number of moles. These properties are related by the ideal gas law: PV = nRT, where P is pressure, V is volume, n is the number of moles, R is the gas constant, and T is temperature.

4. Can a real gas ever behave like a perfect gas?

In certain conditions, a real gas can behave like a perfect gas. This is known as the ideal gas approximation, where the gas molecules are far apart and have low intermolecular forces. This is commonly seen at low pressures and high temperatures.

5. What are some applications of the perfect gas concept?

The concept of a perfect gas is used in various fields, such as chemistry, physics, and engineering. It is particularly useful in studying the behavior of gases under different conditions, such as in chemical reactions, weather patterns, and gas laws. It also serves as a basis for the ideal gas law, which is widely used in calculations and experiments involving gases.

Similar threads

  • Introductory Physics Homework Help
Replies
12
Views
798
  • Introductory Physics Homework Help
Replies
12
Views
735
  • Introductory Physics Homework Help
Replies
7
Views
1K
  • Introductory Physics Homework Help
Replies
15
Views
3K
Replies
6
Views
653
Replies
3
Views
908
Replies
1
Views
125
  • Introductory Physics Homework Help
Replies
1
Views
778
Replies
3
Views
1K
  • Introductory Physics Homework Help
Replies
9
Views
4K
Back
Top