Experiment 125
Analysis of Copper

The object of this experiment is to determine the empirical formula of a compound of copper. The procedure is given on page F-7 in the Supplementary Materials. In order to obtain good results, great care must be taken to obtain the most accurate data possible. The following questions are designed to help you prepare for this experiment.

Part 1.

A 5.31 gram sample of copper chloride gives an apparent yield of 3.04 grams of copper. The theoretical yield is 2.89 grams.
1. The empirical formula of copper chloride is: (Check one of the following)
a. CuCl
b. Cu2Cl3
c. Cu3Cl4
d. Cu2Cl5
2. The theoretical formula is: (Check one of the following)
a. CuCl
b. CuCl2
c. Cu2Cl3
d. Cu2Cl5
3. Possible explanations for the experimental results include: (Check all that apply)
a. The filter paper was included in the final weight, but not in the initial weight.
b. The filter paper was included in the initial weight, but not in the final weight.
c. Some of the recovered copper was lost during the filtration process.
d. The aluminum was not completely removed before the filtration process.
e. The copper was not allowed to dry completely.
f. The copper was dry but the filter paper was still wet.
g. The copper chloride was not allowed to react fully with the aluminum.
h. The solution in the filtration flask after the copper was filtered was blue.