Introduction:
You will perform the replacement reaction shown below. By weighing the iron that is added to the copper(II) solution, and weighing the copper produced in the reaction, you will be able to determine whether iron is oxidized to iron(II) or iron(III).
Cu2+(aq) + Fe(s) -----> Fe+?(aq) + Cu(s) Your introduction should include a statement of the reaction and you should identify what is oxidized and what is reduced in the reaction. You should then write the two balanced equations corresponding to the two possibilities, iron2+ and iron3+. Then, assuming you start with 2.00 g iron, calculate the mass of copper produced in each case.
Procedure
Obtain about 50 mL copper(II) sulfate solution in a 250 mL beaker. Weigh out about 2.00 g of steel wool and place in the copper sulfate solution. Stir with a glass rod, observing any changes in the appearance of the contents of the beaker and recording them in your lab book. Weigh a piece of filter paper and record the weight in your lab book. When all the iron has reacted, filter the copper and rinse thoroughly with distilled water. Let dry overnight and mass the filter paper and beaker.
Calculations
determine the # of moles of iron you used from the mass
determine the # of moles of copper expected for both possibilities (ferrous and ferric) as you did for the prelab
determine the # of moles of copper actually produced (don't forget to subtract the mass of the filter paper!)
Results and Discussion
Which iron ion was produced? Justify. Compare your results with another groups. Do their results agree with yours? Does this reaction agree with what you would expect from the electromotive (activity) series of metals?What were some sources of error in this lab? How could you improve this experiment?
|
Send questions, comments or suggestions to Gwen Sibert, at the Roanoke Valley Governor's School gsibert@rvgs.k12.va.us |
Back to 2002-03 Experiments Menu |