Observing the Effect of Temperature on Change of State and Gas Pressure

The goal of this lab is to get the students thinking about both changes in state and air pressure. I'm going to use this lab to introduce both topics. By guiding them through the discovery of these concepts on their own, my hope is that they'll better understand these concepts when we cover them in class.

This lab will be given in a junior high setting with 9th graders. It should take no longer than a fifty minute class period. To complete this lab, little special equipment is needed other than a heat source, some tongs and aluminum cans. This lab is an introduction to both changes in state and air pressure/the gas laws.

In this lab students will crush a can using air pressure. This lesson will be introduced with a short demonstration of how to complete the lab. I then have my students quickly complete writing a procedure, so they demonstrate an understanding of what to do. They will then complete the lab in groups and then answer a few questions, that will guide them (hopefully) to a full understanding of how the can was crushed. I then introduce changes of state and the gas laws after this lab.
Observing the Effect of Temperature on Change of State and Gas Pressure (Acrobat (PDF) 30kB Aug3 09)
Observing the Effect of Temperature on Change of State and Gas Pressure (Microsoft Word 22kB Aug3 09)

When doing the crush can lab i give the students a few tips:

1. Wait for steam to come out for at least 1 minute before putting it in the cold water.

2. When holding the tongs - palm up so that it's easier to flip into the bucket.

3. Dent the can slightly - this is so that it is easier to hold with the tongs.

We will go over and grade this lab in class. I will then look them over once they are turned in.

9.II.A.7 States of Matter