Stoichiometry Lab: Hard as Nails?
You will consider what the coefficients of a balanced chemical equation mean in physical
laboratory terms. You will react a copper(II) chloride solution with the iron in a nail. You will
then determine the relationship between the amount of iron reacted away, the amount of copper
produced, and the coefficients of the balanced chemical equation.
Pre-Lab Requirements (Due on the First Day):
Write the balanced chemical reaction that occurs when solid iron is placed in a solution of
copper(II) chloride. After the reaction the iron will have a 2+ charge.
In the Lab:
Day One
1. Scrub two nails thoroughly with steel wool to clean the protective coating and any rust
off the surface.
2. Write your names on a 250mL beaker with a Sharpie and mass it using the balance. Find
the mass of the two nails using the balance.
3. Place the two nails in the bottom of a 250mL beaker. Pour roughly 80mL of 1M
copper(II) chloride solution into the beaker. Be sure to add enough solution to
completely cover the nails.
4. Set the beaker in an empty lab drawer to react overnight.
Day Two
5. Using your crucible tongs, carefully remove the nails one by one. Use one of the wash
bottles of deionized water to rinse the stuck on product from the nails back into the
beaker.
6. Place the nails on a paper towel labeled with your names to dry overnight.
7. Carefully pour the liquid in your 250mL beaker down the drain leaving the solid in the
beaker. Be sure not to allow any solid product to go down the drain as it will wreck your
results. This process is called decanting.
8. Wash the solid in your beaker with a 25mL portion of deionized water two times and
decant the liquid off into the sink after each wash.
9. Wash the solid in your beaker with a 25mL portion of 1M hydrochloric acid to remove
any unreacted iron particles or other impurities. Decant the hydrochloric acid into the
sink while running lots of water along with it.
10. Wash the solid one final time with a 25mL portion of deionized water.
11. Place your beaker in the drying oven and the nails in an empty lab drawer to dry
overnight.
Day Three
12. Mass the beaker and product using the electronic balances. Mass the dried nails using the
electronic balances.
13. Place your product and nails in the trash. Be sure to thoroughly clean your product off of
your beaker using steel wool. Have Mrs. Atkins check your beaker to make sure it is
sufficiently clean.
Lab Report: (See Next Page)
Lab Report:
A) Purpose
B) Analysis Questions
1) Show your calculations for the mass of iron that reacted.
2) Show your calculations for the mass of copper that was produced
3) Show your calculations for the moles of iron that reacted.
4) Show your calculations for the moles of copper that were produced.
5) Compare your number of moles of copper and iron to each other and then consider the
balanced chemical equation. What do the numbers in a balanced chemical equation
represent besides just atoms and molecules?
6) Theoretically, you should have produced the same number of moles of copper as the
number of moles of iron that reacted. Compare the amount you should have gotten to
what was expected using the following equation:
%Yield 
Experimental Value
x100 , where the experimental value is the
Theoretical Value
amount of copper you obtained in the lab and the theoretical value is the amount you
should have gotten based on the number of moles of iron that reacted.
7) Suggest two specific errors that would account for your specific % Yield and explain how
they account for your yield. You may NOT say generic things like human error or
inaccuracies of the balance. You must instead come up with specific things that were
done in lab that could account for your % Yield being higher than 100% or lower than
100%. You must then explain how these factors affect your results. If you got exactly
100% yield then give one reason why someone might have gotten a value above 100%
and one reason for a value below 100%.
C) Conclusions
D) Original Data Sheet