Paint Can Experiment

Variation of Reaction Rates

Purpose: The reason of this experiment is to show a dramatic change of rate in a combustion reaction. I hypothesized that when the oxygen in the air and methane enter a balanced state within the can, the pressure will trigger the lid to explode off.

Materials Needed: A one-gallon paint can, a lid for the can with a 0.5 cm hole in the bottom, a lab source of methane gas, a source of flame, air, and a tool to punch a hole in the can.

Procedure:

Take an empty paint can and punch a hole in the lid and several holes near the bottom.

Take the lid off and fill it with gas from gas source.

Put the lid back on and light a flame above the hole.

Move away from the can and explain that in order for the gas to burn it needs oxygen, so the gas burns only as it enters the air.

Explain that if you had the right amount of air inside the can, it would burn inside the can there could even be an explosion.

As you're demonstrating, air will be entering the can from the bottom.

There will be an explosion.

Data- Not applicable.

Results- Not applicable.

Analysis- Not applicable.

Conclusions- The gas within the paint can exploded when the methane gas and the mixture of gases within air, especially oxygen, reached a balanced state where the same amount of methane gas exiting the can is the same amount as how much air is entering the can. This produces pressure to accumulate in the can, which leads to the explosion where the lid pops off. The energy freed appears as heat, light, sound, and kinetic energy which makes the lid fly off. The source of the energy produced by the reaction could be described as the breaking and making of bonds. My hypothesis stated when the methane and air reach a state of balanced amounts within the can, the reaction will cause the lid to fly off, and after the experiment it was proven correct.

Figures and Graphs- Not applicable.

References-

http://www.practicalchemistry.org/experiments/controlled-explosion-of-a-methane-air-mixture,295,EX.html

http://www.thecatalyst.org/download/demos/paint_can.pdf

http://www.fun-science-project-ideas.com/Science-Explosion.html

D. 1. Because the methane gas weighs less than air, it builds up towards the top of the paint can. The

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