SCH3U
Unit 2
Investigations/Activities
Lab Synthesis, Decomposition, and Combustion Reactions
Question
What happens to the elements and compounds in the synthesis, decomposition, and combustion
reactions that are carried out in this investigation?
Materials
Cooper wire, 3 % hydrogen peroxide, manganese (IV) oxide, wooden splints (5), water, calcium carbide,
limewater, tongs, Bunsen burner, test tubes, test tube rack, beaker, stopper
Experimental Design
Part 1
Take a small sample of copper wire and heat it in the flame of a Bunsen burner for about 2 minutes.
Allow it to cool and observe while it cools. Determine the type of reaction occurring.
Part 2
In a test tube lace 10 mL of 3% hydrogen peroxide with 3 g of manganese (IV) oxide. [Manganese (IV)
oxide acts as a catalyst.] Insert a glowing splint to the test tube and identify the gas produced.
Determine the type of reaction occurring and leave the test tube on a rack to cool.
Part 3
Label 3 test tubes at the half way mark, a quarter of the way, and 1/10 the way. Put 500 mL of water
into a beaker and drop a small sample of calcium carbide into it. What type of reaction is occurring?
Invert a test tube full of water into the beaker over the calcium carbide to collect the gas produced. For
the first of 4 test tubes fill it all with gas, for the second fill it half way with gas and the other half will
have the water, for the third test tube fill it with ¼ of gas and the rest is water, for the last test tube fill it
1/10 and the rest is water. For those with water still left in it, let it drain and then immediately stopper
the test tube. Then remove the stopper and put a burning splint into the test tube. When that reaction
is complete add 5 mL of limewater to the test tube and stopper. Shake. Record your observations.
Analysis
Part 1
- What evidence of a chemical change did you observe?
- Write a balanced chemical equation for this reaction?
Part 2
- What gas was produced during the reaction? Explain.
- Write a balanced chemical equation for the reaction.
Part 3
-
In which test tubes did you observe complete combustion? Explain
Write a balance chemical equation for the complete combustion of acetylene gas
In which test tubes did you observe incomplete combustion? Explain
What products formed during the incomplete combustion of acetylene gas?
Why did the amount of soot that was produced in the test tubes vary?
Single Displacement Reaction
Experimental Design
Place a small sample of copper wire into a test tube that is half filled with a solution of silver nitrate.
Analysis
Write a chemical equation for the reaction. Include your reasoning in support of your equation.
Double Displacement Reaction
Question
Will aqueous ammonium phosphate and iron (III) nitrate react and, if so, what will be the products of
the reaction?
Experimental Design
The reactants will be mixed and observed. Determine the evidence you will look for to confirm that a
reaction is proceeding. Write a procedure that will include how to separate any products and how to
identify those products.
Analysis
Write a word equation and a balanced chemical equation.