To ask an engineering question please visit our forum site at Eng-Tips.



Browse our archive of questions and answers below or to access our old forum database of over 10000 questions and answers please visit the old Ask@ forum.

Ideal gas law ?
Last Post 28 Jan 2013 03:57 PM by Niel. 1 Replies.
AddThis - Bookmarking and Sharing Button Printer Friendly
  •  
  •  
  •  
  •  
  •  
Sort:
PrevPrev NextNext
You are not authorized to post a reply.
Author Messages Not Resolved
bonll
New Member
New Member
Posts:9

--
28 Jan 2013 09:18 AM
    In regards to Ideal gas Law / gas constant...

    would the statements below be true?

    The Ideal Gas Law requires that temperature and pressure be converted to absolute values.
    The Ideal Gas Constant R value is: R = 8.3144621(75) J / mol K or
    R = 10.73 ft^3 psi / R lbmol

    Using ideal gas constant R, ft^3 psi / R lbmol, temperature should be in Rankine(R). Rankine is equal to the temperature in Fahrenheit plus 460. It's also worth noting that mass is measured in pounds mol.


    Niel
    Basic Member
    Basic Member
    Posts:193

    --
    28 Jan 2013 03:57 PM
    Actually 1 rankine = -458.67 degrees Fahrenheit. If you are going to be concerned about the uncertainty, the 75 in parentheses they you need to use the exact value of converting Rankine to Fahrenheit temperature. You should also use the Imperial units to the same level of specificity - 10.73159(2)

    Also I am assuming that you are asking about the statement -
    The Ideal Gas Law requires that temperature and pressure be converted to absolute values.

    That statement is basically true. It is describes how gas behaves with regard to absolute press and the temperature scales relative to absolute zero. Remember that if you are talking about per degree in either the Rankine or Kelvin scales the size of each degree is the same as for Fahrenheit and Celsius respectively.

    Niel Leon
    engineering.com

    PS what are you trying to calculate?
    You are not authorized to post a reply.