Purpose: To observe a chemical reaction and explain how a chemical reaction obeys the law of conservation of mass
Materials:
test tube
Test tube clamp
Bunsen burner
Beaker (to hold test tube)
Scoopula
Sparker
Potassium chlorate (KClO3)
Tic-tac candy (C6H12O6) mint
goggles
test tube brush
test tube brush
Caution:
 Wear safety goggles
 Careful when handling Potassium chlorate as it can spark
 Hold test tube open end away from others while heating and reacting
Procedure:
1. Turn on the electronic balance. Place the empty test tube and large beaker on the electronic balance. Zero
out the mass of the beaker and test tube. Add your sample of Potassium chlorate to the test tube and
record the mass of the potassium chlorate. (Data Table)
2. Find the mass of the tic-tac. (Data Table)
3. Add the mass of the tic tac plus the mass of the potassium chlorate and enter it into your data table. (Data
Table)
4. Carefully light the Bunsen burner. Using a test tube clamp, heat the test tube and potassium chlorate over
the Bunsen burner flame until all the crystals melt.
5. Gently shake the test tube without tilting it to check that the substance is now liquid potassium chlorate.
6. Now, drop one Tic-tac mint in the test tube and carefully observe the reaction.
7. After the test tube has cooled down, find the final mass of the test tube + charred remains. (Data Table)
8. Fill test tube with water and soap, then place in empty beaker. You will let this sit for about 10 minutes
while you complete most of your analysis questions.
9. Finish cleaning and thoroughly drying your glassware. Record the mass of the clean, dried test tube in your
data table. (Data Table)
10. Finish your remaining calculations. (Data Table)
Data Table #1: Mass of Reactants
Mass of Potassium chlorate
Mass of tic tac
Total Mass of Reactants
(Tic Tac + Potassium Chlorate)
Data Table #2: Mass of Products
Mass of clean, dry test
Mass of Charred Remains left
tube
in test tube after reaction
Mass of test tube +
charred remains
Mass of gas that escaped during reaction
Total Mass of Products
(Charred Remains in Test Tube + Smoke that left the test tube)
Thornburg 2014
Questions:
1. Label the following as a chemical or physical change and explain why.
a. Potassium chlorate crystals melting
b. Tic-tac reacting with the Potassium chlorate
2. When the Tic-tac was dropped into the Potassium chlorate, in terms of energy, was it an endothermic or
exothermic reaction? (use books to find out what endothermic and exothermic mean) Explain your answer.
3. Where are the tic-tac and the Potassium chlorate when the lab is finished?
4. Explain the difference in the mass of the reactants before the reaction and the mass of the products after the
reaction in terms of the Law of Conservation of Matter.
Thornburg 2014