[Controlled Substance]

Upon trying to determine the freezing point depression constant of cyclohexane in last week's general chem lab, I obtained a value of 55.4 rather than the theoretical value of 20.2degC/molal . This was done by recording and graphing the temperature of a naphthalene/cyclohexane solution in an ice bath.

The teacher said my graphs were ok, and my lab partner came up with the same Kf in her calculations. Did we do the lab wrong?

In doing my lab report I'd like to go beyond saying "this was a non ideal solution". Assuming I got good results, what is it with the interaction of napthalene/cyclohexane which causes this behavior?

As naphthalene shouldn't to my knowledge dissociate in cyclohexane the vant hoff factor is irrelevant here IMHO. However I did see naphthalene is flat and know cyclohexane has conformations through which it constantly switches; I don't see how this could cause such a negative devation from Raoult's vapor pressure law... Through my eyes it seemed that the cyclohexane and naphthalene should have a positive deviation. Although they both normally interact through london dispersion forces it seems they'd get in each others way by their different shapes.

I saw this article, "solubilities of biphenyl and naphthlane in benzene and cyclohexane" whose abstract states they obtained results like ours, but I can't read Korean so the rest is useless to me.  http://www.cheric.org/PDF/HHKH/HK25/HK25-4-0372.pdf

[KritikalMass]

I can't say if you and your partner did the experiment wrong or not since wasn't watching every single thing ya'll did. Maybe your calculations are incorrect or maybe they aren't. There is no telling.

But one thing I have learned in chemistry is that there is always something that doesn't work right or turn out as expected- in fact the vast majority of my experiments I consider utter failures (I have high standards) but almost always get an A on my experiments not because they turned out textbook, but because always presented good  explanations as to why they might not have turned out not so great.

You presented some thought provoking insight into why your experiment didn't produce the expected results. You did research on the subject and sourced it to verify that others have had similar results. If you put the information from this post of yours in your lab report you should definitely get an A. It all shows you have the potential to be a researcher. You presented a good argument which shows you are thinking about the chemistry instead of blindly following the procedure. All of those are good things and good teachers easily pick up on that sort of thinking because it drastically stands out.

Keep up the outstanding work and congratulate yourself on a job well done!

[Controlled Substance]

Hey, turns out our results were a little further off than other groups'.

I already submitted it though, concluding the objectives weren't met and now regret not having included a reference to the article. (My teacher is korean lol) I really do want to make my labs stand out, but I also don't want to make a fool out of myself explaining things wrong or giving reference articles which aren't really related to my labs! 

BTW Thanks for the advice on writing reports! I will keep it in mind for next labs...

[KritikalMass]

Hey, turns out our results were a little further off than other groups'.

I already submitted it though, concluding the objectives weren't met and now regret not having included a reference to the article. (My teacher is korean lol) I really do want to make my labs stand out, but I also don't want to make a fool out of myself explaining things wrong or giving reference articles which aren't really related to my labs! 

BTW Thanks for the advice on writing reports! I will keep it in mind for next labs...

Hey it's all good. If you are worried about looking like a fool you shouldn't. You did some good solid research on the subject and it shows you are thinking, and if you are thinking then a good teacher can lead you in the right direction. I would be interested in seeing how you did on your report so please post your results even if you consider them substandard.

I still say good job and keep it up!