Referencing this paper, I am trying to approximate the order of reaction for cyclohexane (4a). Trials 1-3 provide the relevant information of mmol changes and corresponding percent yield but I'm struggling to see how I can use this to get the reaction order. Am I missing something? Thank you, I appreciate any help!
We don't know why the yield is lower than 100%. It could be because the blue LED was used for a limited time. It could be because the reactants turned into a side product (the GC data might show that). It could be because of product inhibition. Or it could be some combination of these and other factors.
Without at least two data points taken at different times, or prior knowledge of why the yield is less than 100%, you should not make any statements about reaction order.
To be fair, there are intro lab experiments that pretend to get a reaction order without measuring a time trace (use different concentrations of reactants and measure how long it takes to use up a reactant), but they say in the introduction what the underlying assumptions are, and that those have been tested already. Also, they give a range of "allowable" concentrations to make sure you get the "right" answer.
In this case, with the complexity of the reaction mixture including the requirement for photo-catalysis, it seems you can't pull this off. If you naively plot concentration of cyclohexane against yield after 24 h (and assume zero yield for leaving it out altogether), you don't get a curve that fits zero, first or second order.
