Name Date Class
Chapter 19•Acids, Bases, and SaltsEXPERIMENT
REACTIONS OF ACIDS
PURPOSE
To investigate common reactions of acids.
BACKGROUND
Because of its usefulness in many industrial processes, sulfuric acid isone of the most important bulk chemicals produced. The uses of acidsare not limited to industry, however. Artists pull beautiful prints frommetal lithographic plates that have been etched with hydrochloric acid.Hydrofluoric acid is used to etch designs on glass. You encounter naturalacids when you pour vinegar (which contains ethanoic acid) on a salador eat a tart apple (which contains malic acid). Acids can also causeproblems. Acid precipitation can corrode metal; dissolve marble andlimestone statues; and even damage buildings.
In this experiment, you will investigate some common reactions ofacids. These characteristic reactions are often used to test for certainions 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 / paper
iron wire or small nails, Fe
copper wire, Cu
magnesium ribbon, Mg
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. Ifyou see a safety icon beside a step in the Procedure, refer to the list belowfor its meaning.
Caution:Wear your safety goggles. (All steps.)
Caution:Concentrated hydrochloric acid is highly corrosiveand can cause severe burns. (All steps.)
Caution:Magnesium is flammable. Keep it away from openflames. (Step 2.)
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Note:Return or dispose of all materials according to theinstructions 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 tubesin a test-tube rack. CAUTION:Hydrochloric acid is corrosive, especially at the 6M concentration. Add 2 mL of 6M hydrochloricacid to each tube.
2. Obtain the items indicated below and place them on labeledpieces of paper. Using forceps, carefully transfer the materialsto the numbered test tubes, as the following list indicates.
tube 1 / 2-cm length of clean iron wire or a small nailtube 2 / 2-cm length of copper wire
tube 3 / 2-cm length of magnesium ribbon
tube 4 / 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 isproduced. Attempt to identify any gas produced by holding aburning wood splint at the mouth of the test tube. If it appearsno gas is being produced, place the test tube in a holder andwarm 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 thepresence of gas production. Record your observations.
4.Follow your teacher’s instructions for proper disposal of thematerials.
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OBSERVATIONS
DATA TABLE 1: REACTIONS WITH HYDROCHLORIC ACIDSubstance / 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 mostreactive.
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 mostvigorously with hydrochloric acid.
4.Was the same gas produced when sodium hydrogen carbonate and calciumcarbonate reacted with hydrochloric acid? What was the gas? How did you identifythis gas?
5.Write balanced equations for the reactions of sodium hydrogen carbonate andcalcium carbonate with hydrochloric acid.
GOING FURTHER
Develop a Hypothesis
Based on the results of this lab, develop a hypothesis about how the relative strengthof 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 youhave your teacher’s permission, perform the experiment.
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