Limiting Reactants: Copper (II) Chloride and Aluminum
Abstract
The reaction of copper (II) chloride with aluminum was performed to identify the
products formed, type or reaction, theoretical yield of the product, and percent yield of
the product. We combined 2.01675 grams of CuCl2 with 0.20 grams of aluminum. The
theoretical yield of the copper, the precipitate, was 0.705 grams; however, we recovered
1.03 grams of copper. 146% was our percent yield. Our percent error was 46%. We
concluded that this reaction created a single displacement and the limiting reactant is
aluminum.
Introduction
For this lab, we will be reacting copper (II) chloride with aluminum. When we put
these two reactants together, we believe that copper metal and aluminum chloride will
be the products. This is an example of single displacement. We believe that copper
metal and aluminum chloride will be the products because single displacement happens
a lot when copper is involved a reactant. According to WikiEditor.org, our hypothesis
should be correct.
Copper (II) sulfide and aluminum both have a wide range of uses. Copper (II)
sulfide is used as a catalyst for organic and inorganic reactions, mordant with dye for
dyeing and printing textiles, pigment for glass and ceramics, wood preservative,
disinfectant, insecticide, fungicide, herbicide, purifying agent in the petroleum industry,
laundry marking ink, and tint bath for iron and tin. Copper (II) sulfide is very toxic. It is
found naturally in nature; however, it is very rare. Aluminum is used as cans, foils,
kitchen utensils, window frames, and airplane parts. It is the second most malleable
metal. It is usually used as an alloy because aluminum itself isn’t very strong. Aluminum
can form a very reflective coating when it is vacuumed. These aluminum coatings are
used as telescope mirrors, decorative paper, packages, and toys. Aluminum is the most
abundant metal in the Earth’s crust (about 8.2% of the Earth’s crust is made of
aluminum); however, it is never found in its pure form in nature. It is always in a
compound with another element.
Data
1. Grams of copper (II) chloride
Molarity = moles/liters of solution
0.500M = mol/0.03 L
(0.500M)(0.03L) = 0.015 mol
0.015 mol CuCl2
134.45 grams CuCl2
=
2.01675 grams CuCl2
1 mol CuCl2
2. Mass of filter paper: 0.66 grams
3. Mass of aluminum foil: 0.20 grams
4. Observations
Before
-
Aluminum foil (solid) is silver
Aluminum foil is shiny
CuCl2 (liquid solution) is blue
5. Observations of precipitate
After
-
Red, brown solid
Red solid isn’t shiny, it’s dull
Red solid broken in many pieces
Green, grey liquid solution left
-
Color is red, brown
Broken in many pieces
Dull
Easily broken, not strong
6. Mass of precipitate and paper: 1.69 grams
Results
1. Mass of solid:
1.69 grams - 0.66 grams = 1.03 grams
2. Balanced equation:
3CuCl2 + 2Al (s) → 3Cu (s) + 2AlCl3
3. Limiting reactant:
2.01675 grams CuCl2
1 mol CuCl2
=
0.0150 mol CuCl2
134.45 grams CuCl2
0.0150 mol CuCl2 ÷ 3 (coefficient of CuCl2) = 0.005 mol CuCl2
0.20 grams Al
1 mol Al
=
0.00741 mol Al
26.98 grams Al
0.00741 mol ÷ 2 (coefficient of Al) = 0.005 mol Al
Aluminum is the limiting reactant.
4. Theoretical yield
0.00741 mol Al
3 mol Cu
63.55 grams Cu
=
2 mol Al
1 mol Cu
0.705 grams Cu
5. Percent yield
1.03 grams Cu (actual yield)
=
146% yield
0.705 grams Cu (theoretical yield)
6. Type of reaction: Single displacement
Discussion
We reacted copper (II) chloride with aluminum to identify the products formed,
type or reaction, theoretical yield of the product, and percent yield of the product. We
combined 30.0 mL of copper (II) chloride with 0.20 grams of aluminum foil. We
hypothesized that our products would be copper and aluminum chloride. Our hypothesis
was correct. Our limiting reactant was aluminum. We measured our product and saw
that we recovered 1.03 grams of copper. Our theoretical yield was 0.705 grams of
copper. This means we a 146% yield. After all our group members collaborated, we
decided one reason for our error yield was because some of the aluminum chloride was
dried on our filter paper. We also noticed while performing the lab that there was some
copper (II) chloride left in the graduated cylinder after we poured it in the beaker. These
reasons affected the mass of our product. Our conclusion is this was a single
displacement reaction and the precipitate formed was copper.
Acknowledgements
We would like to thank the beautiful Mrs. Nancy Galster. We would like to thank
each other for staying on task and completing the lab successfully. We would also like
to thank the professionals who are willing to read our lab report and watch our
presentations.
Citations
"Aluminium." - Element Information, Properties and Uses. N.p., n.d. Web. 11 Feb. 2015
"Chemistry/Observing Chemical Changes Marking Scheme." - WikiEducator. N.p., n.d.
Web. 13 Feb. 2015.
"National Pollutant Inventory." National Pollutant Inventory. N.p., n.d. Web. 11 Feb.
2015.
"The Element Aluminum." It's Elemental -. N.p., n.d. Web. 11 Feb. 2015.