Combustion Lab
Background
In a combustion reaction, a substance combines with oxygen and released energy in the form of light and heat. During the winter, we use combustion reaction involving wood, corn, and gases to heat our homes. The bright light from magnesium ribbon burning is an example of a combustion reaction.
2Mg + O2 à 2MgO
Many people believe that we are using our fossil fuels up through combustion reactions. In reality, we are just changing how useful they are to use. We never create or destroy any substance during a chemical reaction. It may appear to use that we create a substance when weight is added after a chemical reaction. It may also appear that we use up a substance when the weight becomes less after a chemical reaction. We really have just rearranged the atoms.
Objectives:
-identify a combustion reaction
-construct a chemical equation
-explain a weight change in a combustion reaction
Materials
Fine steel wool, Bunsen burner, matches, electric balance, crucible tongs, goggles, pie pan
Procedure
1.Measure the mass of some unburned steel wool.
2.Measure the mass of a pie pan.
3.Light your Bunsen burner.
4.Hold the base of the burner and ignite your steel wool. Make sure to keep the pie pan under the steel wool at all times.
The pie pan will prevent you from losing product.
5.When the steel wool is done burning, find the mass of the steel wool and the pie pan.
6.Calculate the new mass of the steel wool.
Data
Weight of unburned steel wool:______
Weight of pie pan:
Weight of burned steel wool:______
Difference in weight between burned and unburned steel wool:______
Answer three analysis questions with complete sentences:
1.Why did you need to hold the pie pan under the steel wool as you burned it?
2.Why SHOULD you have seen a change in weight?
3.What was your job in this lab?