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Topic: Calculating 2nd virial coefficient!!!  (Read 16163 times)

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aria152

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Calculating 2nd virial coefficient!!!
« on: September 05, 2005, 04:03:03 PM »
I have been given a set of pressures in bar and their corresponding molar volumes for Hydrogen gas. I have to calculate the 2nd virial coefficient of hydroen at 0 degrees.  
Anybody have any suggestions on how to do it ??
I think  that I am supposed to plot the given values and the grdient is supposed to give me "B" but I do not know how to go about it..
 
 PLease *delete me*!  
« Last Edit: September 05, 2005, 04:09:03 PM by aria152 »

BAL

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Re:Calculating 2nd virial coefficient!!!
« Reply #1 on: September 06, 2005, 11:45:24 AM »
Hello Aria, i dont think to be very helpfull but you can find it in any physical chemistry textbook, you can exprese the B like a function on term of  a Vander-waalls, Dieterichi, constants. jus remember that PV/TR=1=AT+BT2+CT3..., I don't know if the last expresion is correct, I have my book far far away form here, that can give you and idea what I am saying.
Please look for PhysicalChemistry text Book, Atkins or Castellan, yuo will find more information, and tri to calculate A and C is a like a funtion of a Vander Waalls Gas, is a good exercise!

Good Luck!

GCT

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Re:Calculating 2nd virial coefficient!!!
« Reply #2 on: September 07, 2005, 11:38:18 AM »
I have been given a set of pressures in bar and their corresponding molar volumes for Hydrogen gas. I have to calculate the 2nd virial coefficient of hydroen at 0 degrees.  
Anybody have any suggestions on how to do it ??
I think  that I am supposed to plot the given values and the grdient is supposed to give me "B" but I do not know how to go about it..
 
 PLease *delete me*!  

it's P=(RT/Vm)(1+ B/Vm+C/Vm^2....), you have the temperature, if you know the corresponding molar volume and pressure, you should easily be able to solve for P...watch out for the units!!!

Offline gregpawin

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Re:Calculating 2nd virial coefficient!!!
« Reply #3 on: September 08, 2005, 04:15:44 PM »
You can use excel... it has a polynomial fitting... just plot the pressure divided by RT versus the inverse molar volume.... someone please correct me because i haven't done this one before.  then one of the coefficients of the polynomial terms is your virial coefficient
« Last Edit: September 08, 2005, 04:21:33 PM by gregpawin »
I've got nothin'

mhill37

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Re:Calculating 2nd virial coefficient!!!
« Reply #4 on: September 13, 2005, 03:44:17 PM »
There are also several convenient mathematical tools posted here:

http://www.akiti.ca/Mathfxns.html

For example, it includes a utility for solving a Cubic Equation and one for Data Fitting.

Regards,


Michael


aria152

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Re:Calculating 2nd virial coefficient!!!
« Reply #5 on: September 25, 2005, 05:39:57 PM »
thanks guys.. that was really helpful..

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