Kinetic Theory and Thermophysical Properties

In summary, there are ways to derive the viscosity and mass diffusivity of an ideal gas from kinetic theory, with Maxwell being the first to do so. The rate of momentum transfer and average molecular speed play a role in determining these properties, with temperature being a factor for viscosity. Hirschfelder's book, "Molecular Theory of Gases and Liquids" provides theoretical treatments on the topic and can be found in the library.
  • #1
Clausius2
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Is there any way to derive the viscosity [tex]\mu[/tex] of an ideal gas from kinetic theory?

Also: Is there any way to derive the mass diffusitivity [tex] D[/tex] of an ideal gas from kinetic theory?.

Another one: does it make sense to talk about the mass diffusivity of an individual gas (for instance [tex] D_i[/tex]), or such magnitude is always referred to a gaseous mixture (i.e [tex] D_{ij}[/tex])?.

Some web link of bibliography would be greatly appreciated.
 
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  • #2
Clausius2 said:
Is there any way to derive the viscosity [tex]\mu[/tex] of an ideal gas from kinetic theory?

Some web link of bibliography would be greatly appreciated.
Apparently there is. Viscosity of a gas is interesting. It is entirely different than viscosity of liquids. Seems Maxwell was the first to derive it from kinetic theory. See: http://www.math.umd.edu/~lvrmr/History/Foundations.html

"In a gas, viscous force originates not in the forces between neighboring molecules but in the transfer of momentum that occurs when a molecule from a faster-moving stream wanders over to a slower-moving stream and collides with a molecule there. The rate of momentum transfer increases with the average molecular speed, so (1) the viscosity increases with temperature."

AM
 
  • #3
See Hirschfelder, Curtiss, and Bird, Molecular Theory of Gases and Liquids for the theoretical treatments --- it'll be in the library.
 
  • #4
Andrew Mason said:
Apparently there is. Viscosity of a gas is interesting. It is entirely different than viscosity of liquids. Seems Maxwell was the first to derive it from kinetic theory. See: http://www.math.umd.edu/~lvrmr/History/Foundations.html

"In a gas, viscous force originates not in the forces between neighboring molecules but in the transfer of momentum that occurs when a molecule from a faster-moving stream wanders over to a slower-moving stream and collides with a molecule there. The rate of momentum transfer increases with the average molecular speed, so (1) the viscosity increases with temperature."

AM

Thanks both of you.

AM, I am looking for a formulation, not only the historical background of the stuff.
 
  • #5
Bystander said:
See Hirschfelder, Curtiss, and Bird, Molecular Theory of Gases and Liquids for the theoretical treatments --- it'll be in the library.

Thank you very much Bystander. I have found what I was looking for in Hirschfelder's book.
 
  • #6
"The Green Monster" is the repository of all wisdom. You are welcome.
 
  • #7
"The Green and Heavy Monster" by the way. :smile:
 

1. What is Kinetic Theory?

Kinetic Theory is a scientific model that explains the behavior of particles in a gas, liquid, or solid. It states that all particles are in constant motion and that the temperature of a substance is directly related to the average kinetic energy of its particles.

2. How does Kinetic Theory relate to Thermodynamics?

Kinetic Theory is a fundamental part of thermodynamics as it provides a microscopic explanation for macroscopic properties such as temperature, pressure, and volume. It helps to explain the relationship between these properties and the behavior of particles in a substance.

3. What are the main assumptions of Kinetic Theory?

The main assumptions of Kinetic Theory include that particles are in constant motion, collisions between particles are elastic, and there are no attractive or repulsive forces between particles. It also assumes that particles have negligible volume and that the average kinetic energy of particles is directly proportional to temperature.

4. What are some examples of thermophysical properties?

Thermophysical properties are physical properties of a substance that are related to its temperature and energy. Examples include specific heat capacity, thermal conductivity, viscosity, and thermal expansion coefficient.

5. How are thermophysical properties measured?

Thermophysical properties can be measured through various experimental techniques such as calorimetry, thermogravimetry, and thermal conductivity measurements. These techniques involve manipulating the temperature and energy of a substance and measuring its response, which can then be used to determine its thermophysical properties.

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