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Topic: Determining Rate Order/Rate Constant/Ea?  (Read 2086 times)

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Offline Amaethon

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Determining Rate Order/Rate Constant/Ea?
« on: March 20, 2010, 10:06:04 PM »
Hi there, I was hoping that someone could point me in the right direction for my lab calculations. They're frustrating me to no end. So this is a pretty basic kinetics lab, where you run a reaction while altering concentrations to see how things change. Plotting the data should then give you a linear equation that you can use to determine the rate order. I think my data might be a little screwy, because I can't seem to get things to look right. But as I have it now, the rate law I've come up with is:

rate = k' [I-][H2O2]2

As I understand it, trimolecular processes like this aren't even likely to occur. So it's probable that my rate order data is off somehow, right?

In any case, I tried determining k' with this data. My lab book said that  :delta: mol/ :delta: t=k'[I-]p[H2O2]q.

So from my data: 7.1*10-8 mol/sec = k'[0.03][0.03]2

But I can't even figure out what the units would be for (7.1*10^-8mol/s)/(0.03M)(0.03^2M). So frustrated right now. :( Not that it matters terribly, because I can't seem to calculate the rate order properly. I had this one bit of data that I initially regarded as garbage, because it look so nice; For one of my data sets, a "boomerang" shaped line resulted instead of a straight line. The slope for that line was like, 1. This would ultimately result in a bimolecular process rather than a trimolecular process. Should I go with this data instead?

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