Calculating Thermal Conductivity of Argon at S.T.P.

[gemt]

Hi could anyone advise me to weather I am right in thinking when using equation one to calculate the thermal conductivity that C_v is the molar heat capacity and is calculated by use of equation two for an ideal gas such as argon?

k=n*<v>*mfp*c_v / 3*N_A

C_v,m = (3/2) * R

Any hints would be much appreciated as the using the above equations i am getting a result which is about 30% out for the expected value of 1.71e-2 J/W/K for the thermal conductivity of argon at s.t.p

Thanks again in advance

gem

 

[Aaron Barnard]

Yes, you are correct in thinking that Cv is the molar heat capacity and can be calculated using equation two for an ideal gas such as argon. However, there may be other factors contributing to the discrepancy between your calculation and the expected value. For example, you may not be accounting for the contribution of viscosity to the thermal conductivity or the effects of pressure on the gas molecules. Additionally, the equations you are using may not account for changes in temperature or density of the gas.

 

[astrokreng]

Hello gem,

Yes, you are correct in thinking that Cv is the molar heat capacity and can be calculated using equation two for an ideal gas like argon. The equation you provided for thermal conductivity at standard temperature and pressure (S.T.P.) is also correct. However, there could be a few reasons why your calculated value is off from the expected value.

First, make sure that you are using the correct values for the variables in the equation. For example, n should be the number of moles of argon, <v> should be the average velocity of the argon molecules, and mfp should be the mean free path of the molecules. Also, make sure that you are using the correct value for R, which is the gas constant and is equal to 8.314 J/mol*K.

Another possible reason for the discrepancy could be experimental error. Make sure that the values you are using for the variables are accurate and precise. Small errors in measurement can lead to significant differences in the calculated value.

Lastly, it is important to note that the equation you provided is an approximation and may not give an exact value for the thermal conductivity of argon at S.T.P. This could also contribute to the difference between your calculated value and the expected value.

I hope this helps and good luck with your calculations!