[Dkenyon4792]

Measuring the reaction rates of iodide catalyzed decomposition of hydrogen peroxide, we have multiple rate constants, k, at the same temperature for different concentrations of iodide.  From a graph of the rate constant versus the iodide concentration, we are supposed to estimate the order of reaction with respect to iodide.

Now, I have driven myself in circles reasoning this out.  For the above graph, what on earth should it look like?  Positive slope, no slope? 

Thanks in advance for any input!

[mjc123]

Well, what do you think, based on your knowledge of kinetics? (I assume they're not asking you to do this with no knowledge of kinetics!) For a start, do you think rate constant vs. [I^-] is the best graph to plot? If not, what?

[Dkenyon4792]

Well, my assumption was that it was a power law (ln k versus ln[I-]),  a Guldberg Waage derivative, where the slope would correspond to the exponent.  However, I've read that some catalyzed reactions can have a negative slope in this form.  So, to answer your question, I honestly am not sure.

[Irlanur]

the mechanism of a catalytic reaction can basically give you anything. It would be a good start to just plot the graph and look at it. The reaction order is phenomenological anyway.

[Dkenyon4792]

I have plotted it, both as k versus [I-] and as ln k versus ln[I-].  I just want to ensure that I understand the reasoning behind the data and that my data is correct.

[Irlanur]

Do you want to show it?