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Homework Help: Equilibrium Concentration

  1. Feb 11, 2007 #1
    1. The problem statement, all variables and given/known data

    CO(g) + NH_3(g) ...> HCONH_2(g)

    euilibrium constant is: K = 0.207 at 400 K
    If a reaction is filled with intial concentrations 2.20 M of CO and 2.60 M of NH_3 and the reactanats are allowed to raect at 400K/ what will be the concentrations of CO at equilibrium ?

    2. Relevant equations

    Keq = [HCONH_2] / [CO] [NH_3]

    3. The attempt at a solution

    0.207 = (X) /(2.20-X)(2.6-X)

    But I'm getting the wrong answer for x. Please help me.
  2. jcsd
  3. Feb 11, 2007 #2
    ^your equation for x seems correct. i rearranged it to
    0 = 5.72/x - 5.007 + x
    we need to find the zeroes

    when graphed, the zeros are 1.76 and 3.24

    if we use 3.24, we would have a negative concentration of both CO and NH3, which is physically impossible. so, we go with 1.76

    so the answer: 2.2 M - 1.76 = 0.44 M
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