AP Chem Lab: Investigating Copper Reactions

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SUMMARY

The AP Chemistry lab focused on investigating the reactions of copper, starting with 0.500 grams and ending with 0.525 grams, resulting in an impossible percent yield of 105%. The experiment involved creating compounds such as Cu(NO3)2, CuO, Cu(OH)2, and CuSO4. The unexpected increase in mass is attributed to potential errors in lab procedures and the sensitivity of copper to oxidation during heating. Multiple students reported similar high yields, indicating a systemic issue rather than isolated mistakes.

PREREQUISITES
  • Understanding of stoichiometry in chemical reactions
  • Familiarity with copper compounds such as Cu(NO3)2 and CuSO4
  • Knowledge of percent yield calculations in chemistry
  • Basic principles of oxidation and reduction reactions
NEXT STEPS
  • Research the effects of oxidation on copper during heating
  • Study the principles of percent yield and common sources of error in lab experiments
  • Learn about the properties and reactions of transition metals, specifically copper
  • Investigate best practices for isolating and recovering metals in laboratory settings
USEFUL FOR

This discussion is beneficial for AP Chemistry students, educators teaching chemical reactions, and laboratory technicians involved in metal recovery processes.

Eshi
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[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
 
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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 )
 

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