1. Limited time only! Sign up for a free 30min personal 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!

PCHEM/Partial Pressures Question

  1. Sep 11, 2007 #1
    [SOLVED] PCHEM/Partial Pressures Question

    Problem Statement:
    A vessel of volume 22.4dm[tex]^{}3[/tex] contains 2.0 mol H[tex]_{}2[/tex] and 1.0 mol of N[tex]_{}2[/tex] at 273.15K initially. All the H[tex]_{}2[/tex]reacted with sufficient N[tex]_{}2[/tex] to form NH[tex]_{}3[/tex]. Calculate the partial pressures and the total pressure of the final mixture.

    Variables and Magnitudes:
    V = 22.4dm[tex]^{}3[/tex]
    T = 273.15K
    n[tex]_{}H_{}2[/tex]= 2.0 mol
    n[tex]_{}N_{}2[/tex]= 1.0 mol

    First Attempt:
    It takes 1.5 mol of H[tex]_{}2[/tex] to make 1 mol of NH[tex]_{}3[/tex] so I was thinking that I should say that:

    p[tex]_{}H_{}2[/tex] = p[tex]_{}total[/tex]*X[tex]_{}H_{}2[/tex] = ?

    We would need to calculate the total pressure first for this.

    I need a place to start this problem. I just can't put my finger on it.
  2. jcsd
  3. Sep 13, 2007 #2
    After working on the problem some more; I found that there is a simple way to do the problem. Simply find the mole fractions with the number of moles given and calculate the total pressure with PV = nRT for 3 moles, and 22.4dm^3.

    Not much more to it than that. The solution in the book matches up.
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Similar Discussions: PCHEM/Partial Pressures Question
  1. PCHEM Question (Replies: 0)