Prelaboratory Assignment: A 3.0473 g portion of a solid sample which contained copper was dissolved in nitric acid
and diluted to 250.0 mL with distilled water. A 25.00 mL portion of the solution was
diluted with 100 mL of water and electrolyzed at a constant current of 2 mA. After the
electrolysis the mass of the cathode was 10.2485 g. The copper plate was removed
from the electrode by dissolution in nitric acid and the clean electrode had a mass of
10.1005 g. Calculate the percentage of copper in the solid sample.