AP Chem Lab: Investigating Copper Reactions

[Eshi]

[SOLVED] Chem Lab Help!

My AP chem class did an experiment where we started with 0.500 grams of copper and we ended up with 0.525 grams of copper after the experiment. The experiment consisted of us sending copper through different reactions to observe the effects of a series of reactions on the initial sample, and to also see the chemistry of a transition element. We created Cu(NO3)2, CuO, Cu(OH)2, CuSO4, and some other biproducts as well.

the experiment calls for the measuring to be precise and that was accomplished as well as it could be with the tools given. However, the percent yield ended up being 105%, a number that is impossible, obviously something went wrong with the lab, and I was wondering if there were any special properties of Cu that might have caused this increase in final mass. My theory is that the lab procedures allowed for too much error, me and my lab partner were not the only ones to have such a high percent yield, but your thoughts would still be appreciated and very helpful. Thanks

 

[eli64]

that is a great lab.

think about how you isolated/recovered the copper. How might you have gained mass at the end? Copper is quite sensitive to oxidation when it is heated...


(I have seen 130% yields! :D )

 

[Blueshift5]

Thank you for sharing your experience with the AP Chem lab investigating copper reactions. It sounds like you and your classmates were able to successfully conduct the experiment and observe the effects of different reactions on the initial sample of copper.

As for the high percent yield of 105%, there are a few possible explanations for this. One possibility is that the lab procedures may have introduced some sources of error, leading to inaccurate measurements and calculations. Another possibility is that there may have been some unaccounted for reactions or losses during the experiment. It is also possible that there were some special properties of copper that were not taken into consideration during the experiment.

To accurately determine the cause of the high percent yield, it would be helpful to review the lab procedures and calculations to identify any potential sources of error. It may also be beneficial to repeat the experiment and compare the results to see if the high yield is consistently observed.

Overall, it is important to always critically analyze and evaluate experimental results to ensure accuracy and reliability. Thank you for considering the potential reasons for the high percent yield and seeking further understanding of the experiment. Keep up the good work in your AP Chem class!