Percent Yield Lab Guidelines
You will prepare a single replacement reaction, write the balanced
chemical equation, calculate the expected value of copper product,
and calculate percent yield for your reaction. Tabulate your copper
product data on the back board to share with your class. Calculate
the precision for the entire class’s data. Record the entire lab into
your notebook. All sections apply to this lab, as usual.
To perform the reaction, make a copper (II) sulfate solution (exactly
8.0 g of copper (II) sulfate pentahydrate in 50 mL of water). Heat the
solution to just below boiling and stir to completely dissolve. After
removing from heat, gradually stir in precisely 1.55 g of iron filings, a
little bit at a time, stirring continuously. Let the reaction sit and
proceed for 10 minutes, recording observations. To isolate the copper
product, decant iron sulfate solution, then rinse with water and decant
several more times. Gravity filter wet product and allow it to dry until
next class. Do not forget to record the mass of filter paper before
using it. Use wash bottle to get all of copper product out of beaker.
LABORATORY REPORT HELPFUL HINTS:
*When calculating moles of copper sulfate in your calculations
section, get the molar mass from the bottle of copper sulfate instead
of the periodic table!
When writing your discussion of theory, tell which reactant is the
limiting reactant, which reactant is in excess, and explain how you
know, referring to observations from the lab.
When writing your discussion of theory, tell what the role of the water
in the reaction is. Think about particles!