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Homework Help: Calculate degree of dissociation

  1. Oct 30, 2012 #1


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    Gold Member

    1. The problem statement, all variables and given/known data
    Vapour density of [itex]N_2O_4[/itex] which dissociated according to the equation
    [itex]N_2O_4(g) \Leftrightarrow 2NO_2(g)[/itex] is 25.67 at 100°C and a pressure of 1 atm. Calculate the degree of dissociation and [itex]K_p[/itex] for the reaction

    2. Relevant equations

    3. The attempt at a solution
    [itex] \alpha = \frac{D_t-D_o}{D_o} [/itex]

    [itex]D_t = \frac{92}{2}[/itex]
    Plugging in the values does not yield desired answer.
  2. jcsd
  3. Oct 30, 2012 #2


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    Staff: Mentor

    Please elaborate on what you are doing. What are Dt and D0? What is 92?

    Is that the whole question? Either I am missing something or it can't be solved as given.
  4. Oct 30, 2012 #3
    I suppose the OP directly posted the equations without showing how he/she has got it. If i remember correctly, Dt and Do are the theoretical and observed vapour density of a mixture at equilibrium. 92 is the molar mass of N2O4.
  5. Oct 30, 2012 #4


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    Yes thats right. But the answer which I'm getting is wrong.
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