Chemical Forums
Chemistry Forums for Students => Undergraduate General Chemistry Forum => Topic started by: Ciubba on March 03, 2015, 05:35:44 PM
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I ran an experiment in which three reactants produced a colored gas. I varied the initial amount of one reactant while keeping the others constant and then measured how long it took for the absorption (of a complementary wavelength) of the gas to reach .7.
My question now is how do I determine the order?
If I knew the final amount rather than the initial amount, I could plot [A]=[A]0-kt , ln[A]=ln[A]0-kt. amd 1/[A]=1/[A]0+kt and see which plot looked linear, although that would only work for integer powers. Assuming that there is a graphical approach that would work for this situation, but it eludes me. Could someone point me in the right direction? I'm assuming that I can use that fact that A is the same (i.e. the amount of gas produced when absorption=.7) for all of the reactions.
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Start by making C vs time plots.
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Start by making C vs time plots.
I've already done that, but my data are initial concentration until abs=.7 rather than the actual concentration at time t.
I could solve the most linear looking graph for A0 in the integrated rate law, but I'm not sure if that will work. In this case of 1/[A]0=1/[A]-kt it would imply that the y-intercept is actually 1/[A], but I don't believe that is accurate.
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Can you post these plots?
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The left axis is initial concentration with whatever operation performed on it. So, the 1/[A]0 plot has y values of 1/[A]0. The x values are time in seconds until abs=.7.
http://s13.postimg.org/rf4qom7wl/boop.png