1. Not finding help here? Sign up for a free 30min tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Biehle's Nova Physics page 3 error with volume calculation?

  1. Apr 27, 2014 #1
    1. The problem statement, all vbles and given/known data

    So I'm going throught the Nova Physics book and I'm wondering if there's a mistake in calculation. The question reads: How much volume does 0.4kg of oxygen gas take up at T= 27 degrees Celsius and P= 12 atm (gas constant R = 0.0821 L atm/ K Mol).



    2. Relevant equations

    V= nRT/ P
    the text's last two steps for this calculation are: 0.4x1000x0.08x300 / 32 x 12
    the last calculation is: 4x8x300 / 8x50 giving an answer of 24 L.
    Where on earth did the 8x50 denominator come from?


    3. The attempt at a solution

    I keep coming up with 25L, but the text book calculates the volume to be 24L.


    Thanks in advance for any help offered :)
     
  2. jcsd
  3. Apr 27, 2014 #2

    Andrew Mason

    User Avatar
    Science Advisor
    Homework Helper

    It may be a rounding problem. I get 25.6 litres.

    If you want to use V = nRT/P you have to use R = 8.3145 Nm/mol K and P in Pascals (N/m) with 1 atm = 101,325 N/m. Volume will be in m^3 so multiply by 1000 to get litres

    n = 400g/(32 g/mol) = 12.5 mol
    P = 12 x 101,325 = 1,215,900 N/m
    T = 300 K
    R = 8.3145 J/mol K

    V = 1000 x 12.5 x 8.3145 x 300/1.216e6 = 25.6 L.

    AM
     
  4. Apr 27, 2014 #3
    Thanks Andrew for taking the time to respond.
    Yes, without rounding off the initial figures, I come up with an answer of 25.6 L.
    The last stage in calculations in the book confused me when it moved from having a 32x12 denominator to a denominator of 8x50.... I think the last step contains a misprint.
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted



Similar Discussions: Biehle's Nova Physics page 3 error with volume calculation?
  1. Calculating Errors (Replies: 1)

Loading...