Lab: Moles of Iron and Copper
Stoichiometry
Name:___________________________________________Date:______________
Introduction:
Stoichiometry is the quantitative measurement of reactants and products in a
chemical reaction. The Law of Conservation of Mass states that mass, or matter,
cannot be created or destroyed, therefore, amounts of reactants should equal
amounts of products. In this experiment you will react an known amount of iron
with a known amount of copper(II) chloride. You will determine the number of
moles of copper produced in the reaction and number of moles of iron used up in
the reaction. You will then use this information to determine the ration of moles
of iron to moles of copper and compare that ratio to the balanced equation.
Materials:
Reagents:
Beakers
Wash bottle
Drying oven
Steel Wool or sand paper
2 Iron nails
8 g Copper (II) chloride
Distilled water
Hydrochloric acid
Safety:
Copper(II) chloride is poisonous, do not get it in your mouth
Hydrochloric acid is corrosive
Procedure:
1. Mass a clean 250 mL beaker. Record the mass in a data table.
2. Add 8 g of Copper (II) chloride. Record the mass.
3. Add 50 mL of distilled water. Stir and warm to dissolve.
4. Clean 2 iron nails with sand paper or steel wool. Mass and record.
5. Add the nails to the copper (II) chloride solution. Observe the color of the
solution.
6. Next Day: Carefully remove each nail from the solution, keeping any
precipitate in the beaker.
7. Rinse any solid off the nails and lay them on a paper towel to dry. Mass
when dry and record the mass.
8. Decant the liquid from the precipitate in the beaker.
9. After decanting, rinse the precipitate 3 times with 25 mL of distilled water.
10.Rinse the precipitate with 25 mL of hydrochloric acid and once more with
25 mL distilled water.
11.Place the precipitate in the drying oven overnight.
12.Mass the precipitate after it is dry. Record the mass.
Analysis:
1.
2.
3.
4.
5.
6.
7.
Make a Data Table.
Write the balanced equation, an Iron(II) compound is formed.
Calculate the mass of iron used in the reaction.
Convert the mass of iron used to moles.
Calculate the mass of copper precipitated in the reaction.
Convert the mass of copper precipitated to moles.
Calculate the mole ratio of moles of iron used to moles of copper
precipitated.
8. Calculate your percent error using the accepted value of moles of iron to
moles of copper from the balanced equation.
Conclusion:
Explain the concept of stoichiometry and how it was used in this lab. Include any
error that may have occurred in your results.