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A question on determine the rate of formation (chemistry)

  1. Mar 19, 2009 #1
    1. The problem statement, all variables and given/known data
    For the reaction A-->2B+C, the following data are obtained for [A] as a function of time: t=0min, [A]=0.80M; 8min, 0.60M; 24min, 0.35M; 40min, 0.20M.
    Calculate the rate of formation of B at t= 28 min.

    3. The attempt at a solution
    I have found out that this equation is a first order reaction with equation: y=-0.0345145x-0.2270455
    then I plug in the time 28 min into x in this equation and I got the ln=-1.1934515
    the rate for first order of reaction is k* (k=-slope), which is equal to 0.01046386638

    I am wondering did I do the problem correctly? because I was told that it is a wrong answer.
    any comment or help would be great. Thank you very much.
    Last edited: Mar 19, 2009
  2. jcsd
  3. May 24, 2009 #2
    Sorry for bumping this, but I am also having the same problem as the OP. I found the k value to be 3.4×10^-2 and the at that time (which is 35 minutes in my case) to be .24M . I am not sure what I am doing wrong, any help would be great.
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