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Week 2: Reaction rate of nitro compounds

As I head into the last day of week two, I can’t even believe how much I have done in just one week! This week I started three experiments with differing concentrations of iron porphyrin and I started tracking the reaction rate. The data that I was getting is close to what we expect it to be, but there was an anomaly on the curve that made us think about what might have caused it. From there we realized that our glove box (a box filled with nitrogen and helium instead of oxygen) actually had really high levels of oxygen in it. We were able to fix it though, by reviving the oxygen scrubbing catalyst and changing the gas input to a nitrogen and helium mix instead of just pure nitrogen.

Another thing that we eventually realized was letting oxygen into my experiments was the septum that I had used to seal the reaction vial. It was coated with Teflon, so it can’t actually make a tight seal with the glass reaction vial. So we switched septa, hoping that would fix the weird data problems.

As it turns out, there was a problem with the HPLC monitor, there were air bubbles in the syringe that pulls up samples to analyze, which made it so the amount of sample it pulled up, and therefore the reading it gave was off. Since it wasn’t consistently getting the same amount of sample, some of the concentrations I was calculating were looking way off. Today I am re running a few of my experiments through the HPLC, hopefully the problem has been solved.

This week was a lot about trial and error, it was helping me learn how to troubleshoot foreseeable problems this summer, as well as get everything I need for my research into good working order. Now that I know that everything is as it should be, I can finally begin to carry out more experiments and trials and be confident in the data that I receive from them.

I am super excited to finally be getting real data, I can now use my k-observed values for each individual experiment and plot them against the [FeP] molarity, and use the line that I get to obtain a K[FeP] value for nitrobenzene. Basically, my experiments generate a concentration vs time graph, and using about 5 of those graphs, along with the information from their exponential "line of best fit", I can generate a k-observed vs [FeP] and that resulting line will give me the K[FeP]