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8 of 20 |  |
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B-8
Finally, wash the copper metal with 20 to 25 mL of acetone, again, squeezed from a wash bottle. If the
copper metal is dark brown, rewash it with HCl, then water, and finally acetone.
Air-dry the metallic copper by continuing to apply a dynamic vacuum for at least
15 minutes. The product should be bright reddish brown like a new penny. If necessary, dry the copper
metal between two pieces of filter paper. Press the papers together firmly so that the paper absorbs any
residual acetone.
Accurately weigh a vial on an analytical balance. Quantitatively, transfer the copper metal to the vial
using the funnels available on the instructor’s bench and re-weigh the copper metal and vial. Determine
the mass of the copper metal recovered. Label the vial with your name, the mass of copper metal and
the percent yield of copper metal, and turn it in to your laboratory instructor for grading.
Before leaving the laboratory, check to make sure that all of your equipment is clean, and back in to your
drawer. As well, all communal equipment must be cleaned and returned to the designated location in the
laboratory.
Remember to turn in the original copy of the Observations Sheet to your laboratory instructor before
leaving. The second copy of the Observations Sheet should be kept in your laboratory manual for future
reference.
