Name___________________________
Date:
Period:
Introductory Chemical Reactions
Purpose: The purpose of this
experiment is to have you observe a
display of chemical reactions, classify
them and write equations for them.
Each lab team of two students will be
required to run all 10 experiments. It
will be most efficient if people sharing
laboratory tables run different tests.
Although the lab procedure directs
you to write equations, do this after
the lab; use your lab time to perform
the
experiments.
Let
your
observations guide your equation
writing!
Safety: Be sure to wash well any spills
or splashes, and report any spills or
accidents to me, no matter how small
or insignificant they may seem at the
time. GOGGLES MUST BE WORN
AT
ALL
TIMES.
Aprons
recommended.
Materials and Methods:
Normal laboratory apparatus, dilute
and concentrated acids and bases, and
copper (II) carbonate
cobalt (II) chloride 6-hydrate (this
means that each unit has six water
molecules attached to it)
Mg metal ribbon
Solutions of:
silver nitrate
lead (II) nitrate
iron (III) nitrate
copper (II) nitrate
barium nitrate
potassium nitrate
Test 1: Take a 1cm length of Mg
ribbon and a light it from a vigorous
microburner flame. Because of the
intense and dangerous light (high UV)
generated by this reaction, try to
watch the reaction indirectly or out of
the corner of your eye. Collect the
residue (the lab table top is not
suitable receptacle for the residue)
and observe it. Record your
observations in your notebook. Write
the equation for this reaction, and
classify the reaction.
Test 2: In each of two separate small
glasses 13x100mm minitubes mounted
in a stand, place two drops of 15M
ammonia
solution
and
12M
hydrochloric acid solution (The more
concentrated solutions have the higher
“M” numbers and are particularly
dangerous). Dip a dry glass stirring
rod into the minitube containing the
hydrochloric acid solution and
carefully withdraw it so that a droplet
of the solution remains on the end.
Hold the glass rod with the suspended
droplet just above the mouth of the
minitube containing the ammonia
solution. Be sure to prevent the
droplet of hydrochloric acid from
falling into the ammonia solution.
Observe carefully, from the side, and
record your observations. Write the
equation for this reaction, and classify
the reaction.
Test 3: Place a small portion of cobalt
(II) chloride 6-hydrate in a clean and
dry minitube. Hold the tube with the
wire test tube holder and gently heat
the crystals in a nonluminous flame
using the microburner. Record your
observations in your notebook. Write
the equation for this reaction, and
classify the reaction.
Test 4: Let the minitube cool for a few
minutes (while you’re running some
other tests) and then add one or two
drops of deionized water to the
residue obtained from test 3. Record
your observations in your notebook.
Write the equation for this reaction,
and classify this reaction.
Test 5: Place a small portion of copper
(II) carbonate in a clean and dry
minitube. Add 2M hydrochloric acid
solution a drop at a time until no
further reaction occurs (effervescence
resulting from the production of
carbon dioxide gas will occur, and
water is another reaction product).
Record your observations in your
notebook. Write the equation for this
reaction, and classify the reaction.
Test 6: Place a small portion of copper
(II) carbonate in a clean and dry
minitube. Heat gently. Record your
observations in your notebook. Write
the equation for this reaction, and
classify the reaction. Carbon dioxide is
one of the reaction products.
Test 7: To the residue from test 6,
carefully add one or two drops of 12M
hydrochloric acid solution. Record
your observations in your notebook.
Write the equation for this reaction,
and classify the reaction.
Tests 8-10: For these tests, use the
microscale well plates as your reaction
chambers. Add a few drops of one
reagent to another in the well plate,
and then stir with half of a toothpick.
Perform tests 8-10 with the
nitrate solutions.
Test 8: Add a few drops of 2M
hydrochloric acid solution to a few
drops of each of the six nitrate
solutions. If a reaction occurs, write
the net ionic equation for the reaction.
Test 9: Again load a few drops of the
six nitrate solutions into the well plate.
This time, add a few drops of 1M
sodium hydroxide solution. If a
reaction occurs, write the net ionic
equation for the reaction.
Test 10: Load the well plate once more
with the six nitrate solutions. Add a
few drops of 1M sulfuric acid solution
to each. If a reaction occurs, write the
net ionic equation for the reaction.
The well plates must be meticulously
cleaned when you are finished. Use a
cotton swab to clean out each
individual well used in your tests if
any residue remains. They do not have
to dry when stored but they must be
well rinsed with deionized water.
Results and Discussion: Present your
data in readable format (refer to the
lab prep board, “Parts of a Lab
Report” if you are unsure of what to
include). Include observations and
balanced equations with classifications
in the result section. Include state
designators with all equations. Discuss
possible sources of experimental
error.
You may write the equations
freehand in your otherwise typed
report. Record observations in a
concise and specific manner. Write net
ionic equations for any results from
tests 8 – 10 where a ppt formed. For
example, in a test where solutions of
silver nitrate and sodium chloride are
mixed, a result may look like this:
“Test 11:”
AgNO3(aq) + NaCl(aq) → NaNO3(aq) + AgCl(ppt)”
“White ppt AgCl”
In this experiment, all the double
displacement rxns involve nitrates as
reactants, so one of the products has
to be a soluble nitrate as well (the
insoluble ppt can’t be a nitrate).