Experiment 1: Synthesis of Copper Compounds
This experiment involves the synthesis of compounds originating from pure solid copper. By applying solubility rules and the reactive properties of substances, many compounds which would otherwise be costly to extract from nature are able to be synthesized in the laboratory. Laboratory synthesized may sometimes be more economical than natural extraction, however it poses its own problems with the amount of substance that is actually yielded from the production reactions (Stathopulos, 2007). Almost no reaction has 100% yield, thus scientists inadvertently produce undesired products that must be filtered or decanted out of solution (Petrucci et al, 2007). Beginning with pure copper wire, this experiment will exhibit its transformation to substances including Cu(NO3)2, Cu(OH)2, CuO, CuSO4 . 5H2O and finally returning to pure copper (Cu). The experiment objective is to successfully complete these conversions and then calculate the percentage of recovered copper using the initial and final mass data obtained. Procedure
Please refer to "Experiment 1: Synthesis of Copper Compounds" on pages 11-13 in the CHEM 120L lab manual for the procedure outline. All steps were followed without deviation. Results and Observations
Please refer to the calculations and tables (16) located on the following 2 pages.
INITIAL MASS (copper wire) 1.120g FINAL MASS (recovered copper dish mass) 37.88g % Recovery = Recovered mass / Initial Mass . 100 = 37.88g / 1.120g . 100 = 3382%
Table 1- Reaction of Cu with Nitric Acid
Cu + 4HNO3 Cu(NO3)2 + 2NO2 + 2H2O
Nitric acid dissolved copper wire completely
A brown gas was produced
Black precipitate formed
Table 2- Formation of Cu(OH)2
Cu(NO3)2 + 2NaOH Cu(OH)2 + 2NaNO3
Solution turned from a bright blue colour to a very dark blue
Solution turned from very light to extremely thick,...
References: CRC Handbook of Chemistry and Physics, http://www.hbcnetbase.com
R.H Petrucci, W.S. Harwood, F.G Herring and J.D. Madura, General Chemistry (Principles and Modern Applications), Prentice Hall, Ninth Ed., 2007, p. 127.
S. Stathopulos, First Year Chemistry: Chem 120L Lab Manual, University of Waterloo, 2007, p. 10-13
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