University of Bridgeport Aluminium and Its Compounds Experiment Project i just want u to rewrite the the purpose of the experiment and the back ground information with ur own words and the same for the procedure. please see the attachment Prepared by M. L. Gillette, Indiana University Kokomo, and
H. A. Neidig, Lebanon Valley College
PURPOSE OF THE EXPERIMENT
Observe some reactions of aluminum and its compounds. Synthesize alum
from aluminum foil.
Aluminum (Al) is among the most abundant of all elements, accounting for
6.5% by mass of the atoms in the Earth’s crust. The primary ore from which
we obtain aluminum is bauxite, a mixture of hydrated aluminum oxide
(Al2O3•x H2O), iron(III) oxide (Fe2O3), and silicon oxide (SiO2).
The Al–O bonds in Al2O3 are so strong that no common chemical
reducing agents can convert Al3+ ion in the ionic oxide to metallic aluminum,
Al. Large-scale reductions of Al2O3 to Al were first performed by adding
sodium or potassium metal to liquefy Al2O3. These reductions were excee-
dingly expensive; therefore, aluminum was considered a precious metal.
However, as a result of the independent work of Hall and Heroult in
1886, a less expensive method of aluminum production was developed, one
that is still used today. In the Hall-Heroult process, purified Al2O3 is mixed
with a solvent, cryolite (Na3AlF6), prior to electrolysis. The Al2O3-Na3AlF6
mixture melts at a considerably lower temperature than does pure Al2O3,
greatly reducing the amount of energy required for electrolysis, which
dramatically lowers the cost. The electrolysis reaction for the process is
shown in Equation 1.
2 Al2O3(s) + 3351.4 kJ → 4 Al(s) + 3O2(g)
of collecting aluminum beverage cans and melting them down
for refabrication is much less costly than the original reduction of aluminum
from bauxite. Therefore, our nationwide effort to recycle aluminum cans
conserves both aluminum and energy.
© 1995 Cengage Learning
CENGAGE © 1995 Cengage Learning
. ALL RIGHTS RESERVED. No part of this work covered by the copyright herein may be reproduced,
transmitted, stored or used in any form or by any means graphic, electronic, or mechanical, including but not limited to photocopying
recording, scanning, digitizing, taping, Web distribution, information networks, or information storage and retrieval systems, except as
permitted under Section 107 or 108 of the 1976 United States Copyright Act, without the prior written permission of the publisher
copper(II) sulfate-toxic and irritant
95% ethanol-flammable and highly toxic
6M hydrochloric acid-toxic, corrosive, and moisture sensitive
3% hydrogen peroxide solution-corrosive and oxidant
3M potassium hydroxide-toxic and corrosive
4M sulfuric acid-corrosive and toxic
Wear departmentally approved eye protection while doing this experiment.
I. Synthesizing Alum
A. Dissolving Al Foil in Basic Solution
Determine the mass of a piece of weighing paper. Record this mass on
Data Sheet 1.
Cut or tear 1 x 1-cm pieces of Al foil. Transfer foil pieces onto the
weighing paper until the mass of the foil is 0.450-0.500 g. Record the exact
mass of the foil plus weighing paper on Data Sheet 1. Transfer the foil into a
clean 150-ml beaker labeled with your initials.
Hydrogen, a flammable gas, is a product of the reaction between 3M KOH
solution and Al foil. Your laboratory instructor will tell you whether or not to carry
out this step under a fume hood.
The reaction starts slowly because the KOH must first dissolve the protective
coating on the foil. Once the Al is exposed, the reaction becomes vigorous and
3M KOH solution is toxic, corrosive, and can cause burns. Prevent eye, skin,
and clothing contact. Avoid ingesting the solution. If you spill any of this solution,
immediately notify your laboratory instructor.
Using a 25-mL graduated cylinder, add 13 mL of 3M KOH solution to
the Al foil in the 150-ml beaker. Use a glass stirring rod to stir the foil pieces
in the KOH solution until the reaction begins to proceed vigorously. Use
your stirring rod to move any foil pieces clinging to the beaker sides into the
Following complete dissolution of the foil, record your description of
the reaction mixture on Data Sheet 1.
Rinse the graduated cylinder twice, using 5 mL of tap water each time.
Transfer the rinses into a container provided by your laboratory instructor
and labeled “KOH Rinses.”
NOTE: Your laboratory instructor will describe and demonstrate a satisfactory method
for folding filter paper and filtration.
Prepare a funnel and filter paper as shown in Figure 1. Attach a ring
support to a support stand. Prepare a piece of 7-cm filter paper for filtration.
Fit the paper into a short-stem filtering funnel, and place the funnel in the
ring support. Label a clean 150-ml beaker with your initials. Place the
beaker under the funnel stem. Moisten the paper with 2–3 mL of distilled or
deionized water, collecting the water in the beaker.
Transfer the dissolved [Al(OH)4] ion solution onto the moistened filter
paper. Rinse the sample beaker twice, using 2-3 mL of distilled water each
time. Transfer the rinses to the filter paper.
Rinse the residue and filter paper with 2-3 mL of distilled water,
collecting the rinse in the beaker. When the liquid has drained from the
paper and its contents into the container provided
by your laboratory instructor and labeled “Discarded Filter Paper.”
1995 Cengage Learning
A gravity filtration apparatus
Purchase answer to see full