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Chapter 19 • Acids, Bases, and Salts
EXPERIMENT
REACTIONS OF ACIDS
PURPOSE
Text Reference
Section 19.4
To investigate common reactions of acids.
BACKGROUND
Because of its usefulness in many industrial processes, sulfuric acid is one of the
most important bulk chemicals produced. The uses of acids are not limited to
industry, however. Artists pull beautiful prints from metal lithographic plates that
have been etched with hydrochloric acid. Hydrofluoric acid is used to etch
designs on glass. You encounter natural acids when you pour vinegar (which
contains ethanoic acid) on a salad or eat a tart apple (which contains malic acid).
Acids can also cause problems. Acid precipitation can corrode metal; dissolve
marble and limestone statues; and even damage buildings.
In this experiment, you will investigate some common reactions of acids.
These characteristic reactions are often used to test for certain ions or metals.
MATERIALS (PER PAIR)
safety goggles
glass-marking pencil
6 small test tubes
test-tube rack
dropper pipet
forceps
2 spatulas
test-tube holder
gas burner
6M hydrochloric acid, HCl C
T
paper
iron wire or small nails, Fe
copper wire, Cu
magnesium ribbon, Mg F
zinc strips, Zn,
0.25 mm  0.5 cm  2.00 cm
sodium hydrogen carbonate,
NaHCO3
calcium carbonate, CaCO3
wood splints
matches
SAFETY FIRST!
In this lab, observe all precautions, especially the ones listed below. If you see a
safety icon beside a step in the Procedure, refer to the list below for its meaning.
Caution: Wear your safety goggles. (All steps.)
Caution: Concentrated hydrochloric acid is highly corrosive and can
cause severe burns. (All steps.)
Caution: Magnesium is flammable. Keep it away from open flames.
(Step 2.)
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Note: Return or dispose of all materials according to the instructions of
your teacher. (Step 4.)
PROCEDURE
As you perform the experiment, record your observations in Data Table 1.
1. Label six small test tubes with the numbers 1–6. Place the tubes in a
test-tube rack. CAUTION: Hydrochloric acid is corrosive, especially
at the 6M concentration. Add 2 mL of 6M hydrochloric acid to each
tube.
2. Obtain the items indicated below and place them on labeled pieces of
paper. Using forceps, carefully transfer the materials to the numbered
test tubes, as the following list indicates.
tube 1
tube 2
tube 3
tube 4
2-cm length of clean iron wire or a small nail
2-cm length of copper wire
2-cm length of magnesium ribbon
small strip of zinc
Using a spatula, transfer the following materials to the numbered
test tubes as indicated.
tube 5
pea-sized quantity of sodium hydrogen carbonate
tube 6
pea-sized piece of calcium carbonate
3. Observe the tubes for several minutes to determine if a gas is produced.
Attempt to identify any gas produced by holding a burning wood splint
at the mouth of the test tube. If it appears no gas is being produced,
place the test tube in a holder and warm the tube gently, without
boiling, in a burner flame. CAUTION: Do not point the mouth of the
tube toward yourself or anyone else. Remove the tube from the flame
and test for the presence of gas production. Record your observations.
4. Follow your teacher’s instructions for proper disposal of the materials.
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OBSERVATIONS
DATA TABLE 1: REACTIONS WITH HYDROCHLORIC ACID
Substance
Observations
iron
copper
magnesium
zinc
sodium hydrogen carbonate
calcium carbonate
ANALYSES AND CONCLUSIONS
1. List the four metals tested in order of increasing reactivity with hydrochloric acid. List any nonreactive metals
first, then the least reactive, and so on, up to the most reactive.
2. Was the same gas produced when all the metals reacted with hydrochloric acid? What was the gas? How did you
identify the gas?
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3. Write a balanced equation for the reaction of the two metals that reacted most vigorously with hydrochloric acid.
4. Was the same gas produced when sodium hydrogen carbonate and calcium carbonate reacted with hydrochloric
acid? What was the gas? How did you identify this gas?
5. Write balanced equations for the reactions of sodium hydrogen carbonate and calcium carbonate with
hydrochloric acid.
GOING FURTHER
Develop a Hypothesis
Based on the results of this lab, develop a hypothesis about how the relative strength of the acid used would affect the
rate of the reaction with metals and carbonates.
Design an Experiment
Propose an experiment to test your hypothesis. If resources are available and you have your teacher’s permission,
perform the experiment.
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