Name: ____________________________________ Period: _________ Date: ____________________
Lab #3: Turning Iron into Copper
Objective: To use the mole calculations skills you have developed in order to carry out a chemical
reaction with the correct quantities.
Introduction:
Iron filings will react with copper (II) sulfate (CuSO4) in a one to one ratio (1 mole to 1 mole), according
to the following chemical equation:
Fe(s)
iron filings
+
CuSO4(aq)

copper (II) sulfate
blue
FeSO4(aq)
iron (II) sulfate
green
+
Cu(s)
copper
In the reaction, iron will be the limiting reagent. In other words, it will all be used up in the reaction.
Copper (II) sulfate will be in excess; not all of it will be used up in the reaction. Since the number of
moles of iron that reacts will be equal to the number of moles of copper produced, the number of copper
atoms produced should be the same as the number or iron atoms we start with.
You will first make a copper sulfate solution by dissolving copper sulfate crystals in hot water. You will
then add the iron filings to begin the reaction.
Pre-Lab Calculations: Include correct UNITS, WORK, and SIG FIGS.
1. To make the solution of copper sulfate, you will need 5.00 x 10-2 moles of CuSO4•5H2O. Calculate
the mass of CuSO4 •5H2O you need and enter it into the table below.
2. You will dissolve the CuSO4 in 1.67 x 1024 molecules of H2O. Calculate the mass of water that
contains this many molecules.
3. Lastly, you will add 0.040 mol of iron to the copper sulfate solution. Calculate the mass of iron you
will need to weigh out.
Substance
Mass needed (g)
Copper (II) sulfate, CuSO4 •5H2O
Water, H2O
Iron, Fe
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Data Table
Mass of empty 100-mL beaker
25.63
Mass of beaker + copper (after drying)
27.85
Observations of reaction
The solution was
adding the iron,
at the bottom of
of the solution.
blue in color.
originally a deep blue. After
a reddish-brown solid appeared
the beaker and floating on top
The solution turned greenishThe iron seemed to disappear.
Analysis: Include correct WORK, UNITS, and SIG FIGS.
1. How many grams of copper did your reaction produce?
2. How many atoms of Fe did you start the reaction with?
3. How many atoms of Cu did you have at the end of the reaction?
Questions:
1. Why we were you able to convert your mass of water into volume of water by just changing the units
to milliliters in step #4 (ex. 15 g = 15 mL)?
2. Before the reaction you could clearly see the iron. When the reaction is complete, where has the iron
gone? What evidence supports your answer?
3. The introduction of this lab states that “the number of copper atoms produced should be the same as
the number or iron atoms we start with.” Did your data support this statement? Explain.
4. The name of this lab is “Turning Iron into Copper.” During the course of this lab, did you turn iron
atoms into copper atoms? Suggest a more accurate name for the change that took place.
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Lab: Turning Iron into Copper
Materials:
Cupric sulfate pentahydrate (CuSO4•5H2O)
Iron filings (Fe)
Water in wash bottle
Beaker, 100 mL
Beaker, 250 mL
Glass stirring rod
Hotplate
Thermal pad/wire gauze
Weighing dish (small Dixie cup)
Balance
Safety: Cupper (II) sulfate is a skin and respiratory irritant. It is toxic by ingestion and inhalation. Wear goggles at
all times. Be sure to wash your hands thoroughly at the end of the experiment.
Procedure:
1.
Weigh a clean, dry 100 mL beaker. Record the mass in the data table.
2.
Label the beaker with your initials and period.
3.
Weigh out your mass of copper (II) sulfate in the previously-weighed 100 mL beaker.
4.
Convert your mass of water into volume of water. (Ex: If you need 15 grams of water, you will
measure out 15 mL of water). Measure out this volume using the 100-mL graduated cylinder.
5.
Add the water to the 100 mL beaker containing copper (II) sulfate.
6.
Weigh out the mass of Fe filings into a Dixie cup. Set aside until Step 9.
7.
Using a hotplate, heat the beaker of copper (II) sulfate and water and stir with a glass stirring rod
until all of the blue solid dissolves. (Do NOT boil the solution).
8.
When all the crystals are dissolved, stop heating, remove from the beaker from the hotplate, and
place it on a thermal pad or wire gauze.
9.
While stirring, carefully add the iron filings to the hot copper sulfate solution.
10. When all the iron has been added, let the solution react for ten more minutes.
11. Stir it occasionally and record any observations (e.g. color of the solution, appearance and/or
disappearance of solids).
12. When the ten minute reaction time is up, decant the liquid into a 250 mL beaker.
‒ Decanting is the process of carefully pouring off the liquid portion of the mixture, while leaving
the solid at the bottom of the original container. A stirring rod is placed into the new container to
direct the flow of the liquid and prevent splashing.
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13. To wash the solid, add about 10 mL of water to the 100 mL beaker. Stir vigorously then let the solid
settle to the bottom.
14. Decant the liquid into the 250 mL beaker.
15. Repeat the washing and decanting two more times.
16. Spread the solid out on the bottom of the 100 mL beaker and leave it on your lab shelf or desk to dry
overnight.
17. Weigh the beaker and dry copper metal. Record the mass in the data table.
Clean up and disposal:




Wipe up any spills with wet paper towels and dispose of them in the trash.
Dispose of the decanted liquid in the WASTE BEAKER on the back lab bench.
Leave the solid copper in its beaker.
Clean all equipment and glassware.
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