Some specific guidelines for
the Copper Sulfide lab report
- You will need to include all sections in this report (although, as always, you may simply reference the lab manual rather than write out the entire procedure if you followed exactly the instructions in the manual).
See the CH 221 Lab Manual, pages 11-13, for the list of sections that are required in a lab report.
- Theory - You should discuss transition metals and why they have multiple
oxidation states (as opposed to, say ,Group I metals which are always +1). What are the common states of copper?
Use them
to predict the possible formulas of your product. What are possible side
products (i.e. compounds other than the anticipated product that could also
form under these conditions. (Hint - consider things like the presence of
oxygen). One paragraph should be sufficient here.
- Calculations - be sure you do all the calculations mentioned in the lab
manual.
- Error Analysis - be sure you do all the calculations and answer all the
questions pertaining to error that are mentioned in the lab manual (page 54).
- Be sure you consider significant figures! You should be able to
justify your choice of the number of significant figures you use in your
answer. If your class data contains values of varying numbers of sig.
figs. (which is quite likely) don't worry about it, just report your answers
to the number of sig. figs. that you feel are appropriate given the data you
have to work with.
- You are required to do four things in the part of the Copper Sulfide
experiment labeled Results and Conclusions (pages 54-55). Please do
these in the Questions section of your lab report and number them 1 through
4, just as they are in the lab manual. The fourth question should read
like this:
4. A
non-integer y value might have arisen from any one of the following:
a) some of the copper remained unreacted
b) some unreacted sulfur was left inside the crucible
c) possibly a second product was also formed (any ideas on
what it could be?)
Explain how each of the possibilities would affect the value of y (e.g.
would some unreacted copper make the experimental value for y higher or
lower than it should be?