Ideal Gas Heat Capacity Regression Coefficients

In summary, the conversation is about finding a comprehensive list of empirical coefficients for calculating ideal gas constant pressure heat capacities. The speaker has found empirical constants for the Shomate equation but is looking for data in a table. They have also tried searching through NIST-JANAF thermochemical tables and the API Technical Data Book, but have not been successful. The book "The Properties of Liquids and Gases" by Reid et al. has a comprehensive list of empirical constants, but uses a different equation form. The speaker has found a table and a book that have empirical constants for their desired equation, but is wondering if there are any other references available. They suggest trying C. A. Passut and R. P. Danner's
  • #1
cjc0117
94
1
I'm trying to find a comprehensive list of the empirical coefficients to be used in the following equation for calculating ideal gas constant pressure heat capacities:

[itex]\frac{c^{IG}_P}{R}=A+BT+CT^{2}+DT^{-2}+ET^{3}[/itex]
(Eqn. 1)​

cPIG is the ideal gas constant pressure specific heat capacity; R is the universal gas constant; A,B,C,D,E are the empirical constants; T is temperature

I've found empirical constants for the Shomate equation (similar to Eqn. 1 above except that T is replaced with t=T/1000) for a limited number of chemicals, but I can't find this data in a table.

I've tried following links to NIST-JANAF thermochemical tables, and I've tried looking in the API Technical Data Book to no avail (it may be there but I just can't find it amongst all the other data).

"The Properties of Liquids and Gases" by Reid et al. has a comprehensive list of empirical constant but they use an equation in this form instead:

[itex]\frac{c^{IG}_P}{R}=A'+B'T+C'T^{2}+D'T^{3}+E'T^{4}[/itex]
(Eqn. 2)​

I suppose I could fit data derived from Eqn. 2 to Eqn. 1 if I need to. I just want to see if I can find references that use Eqn. 1.

The table at this link, http://www.personal.utulsa.edu/~geoffrey-price/Courses/ChE7023/HeatCapacity-HeatOfFormation.pdf, and the book "Engineering and Chemical Thermodynamics" by Koretsky has empirical constants for Eqn. 1. That's all I've been able to find.

Does anybody know of any other references I could use? Thanks.
 
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  • #2
Try C. A. Passut and R. P. Danner, Ind. Eng. Chem. Proc. Des. Dev., 11: 543, 1972 or
T. E. Daubert, Ibid., 13: 193, 1974
 

Related to Ideal Gas Heat Capacity Regression Coefficients

What is the purpose of calculating Ideal Gas Heat Capacity Regression Coefficients?

The purpose of calculating Ideal Gas Heat Capacity Regression Coefficients is to determine the relationship between a gas's temperature, pressure, and volume and its heat capacity. This information can be used to predict how a gas will behave under different conditions, which is important in various scientific and engineering applications.

How are Ideal Gas Heat Capacity Regression Coefficients calculated?

Ideal Gas Heat Capacity Regression Coefficients are typically calculated using experimental data, such as temperature, pressure, and volume measurements. These values are then plugged into a regression equation, which uses statistical methods to determine the coefficients that best fit the data. This process is often repeated multiple times to ensure accuracy.

What factors can affect Ideal Gas Heat Capacity Regression Coefficients?

There are several factors that can affect Ideal Gas Heat Capacity Regression Coefficients, including the type of gas being studied, the temperature and pressure range being tested, and the accuracy of the experimental data. In addition, the type of regression equation used and the assumptions made about the gas's behavior can also impact the coefficients.

What are some common applications of Ideal Gas Heat Capacity Regression Coefficients?

Ideal Gas Heat Capacity Regression Coefficients are commonly used in thermodynamics, chemistry, and engineering to predict the behavior of gases under different conditions. This information can be applied to the design and optimization of processes and equipment, such as in the production of industrial gases or in the development of new energy technologies.

Are there any limitations to using Ideal Gas Heat Capacity Regression Coefficients?

While Ideal Gas Heat Capacity Regression Coefficients can be useful in predicting the behavior of gases, they are based on idealized assumptions and may not accurately reflect the behavior of real-world gases. Additionally, these coefficients are typically only applicable within a certain temperature and pressure range, and may not accurately predict behavior outside of these limits.

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