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Homework Help: How to find the integrated rate law?

  1. May 12, 2008 #1
    1. The problem statement, all variables and given/known data

    Find the integrated rate law for a first order reaction


    3. The attempt at a solution

    We have r = -d[A]/dt = k[A]

    Integration with respect to [A] gives

    [A] = (1/2)k*[A]^2

    Is this it?
     
  2. jcsd
  3. May 12, 2008 #2
    d[A]/dt = k[A]

    1/(k*[A]) . d[A] = dt

    1/(k*[A]) . d[A] = t

    now integrate left side ..

    I am pretty sure that you have got it wrong
     
  4. May 12, 2008 #3
    ln[A] + [A]0 = kt

    Is this the correct form?
     
    Last edited: May 12, 2008
  5. May 12, 2008 #4
    ln[A] + C = kt

    Can anyone explain why the integration constant is ln[A]0?
     
  6. May 13, 2008 #5
    that's due to the integration limits
    {from 0 to t}
    ln(A) is at t and ln[A]0 is 0
     
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