A question on determine the rate of formation (chemistry)

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SUMMARY

The discussion centers on calculating the rate of formation of product B in the first-order reaction A → 2B + C using concentration data over time. The participants utilized the equation y = -0.0345145x - 0.2270455 to derive the concentration of B at t = 28 minutes, resulting in [B] = 0.303M and a rate constant k of 0.01046. However, discrepancies arose regarding the accuracy of these calculations, with another participant reporting a k value of 3.4×10^-2 and [B] = 0.24M at t = 35 minutes, indicating potential errors in the application of the first-order kinetics formula.

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Kudo Shinichi
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Homework Statement


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.

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
=exp(-1.1934515)=0.3031730544
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:
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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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