Question

This lab illustrates atmospheric pressure and the gas laws. You will need an empty aluminum drink can, or two or three, .... a heat source, a bowl or pan of cold ice water. Use tongs when handling the can to keep from burning your self. Use an empty soft drink can. Put a small amount of water in the bottom of the empty can - about enough to cover the bottom well. Place the can on a heated stove burner and heat the water to boiling. Wait until the water in the can comes to a good boil and steam is coming from the opening of the can. Using tongs, quickly remove the can from the heat and immediately invert it while putting the can into a bowl of icy cold water. This is one of the activities that I have gotten the most feedback on. Have fun! Submit your report with complete sentences, paragraphs, and correct punctuation and grammar. I'm looking for three paragraphs. In the first paragraph describe what you did. In the second paragraph describe what you observed or what happened, and in the third paragraph explain why this happened, or the meaning of your observations

Answer 1

Experiment:

A little bit of water (about 50ml) was poured into the soft drink can. The water was gradually heated so that it'll boil and give off steam. After a little time, when the steam was boiling off vigorously from the opening of the can, it was removed from the stove by the tongs and almost immediately inverted while it was being put into a bowl of icy cold water.

Observation:

While the can was heated there was a hissing sound first. Then sound of boiling came from the can. White steam was escaping from the opening. The can imploded almost instantaneously when was put into the bowl of icy cold water.

Conclusion:

When the can was heated water started to boil and circulating convection current inside the liquid makes the hissing sound. When the water was vigorously boiling it produced steam. Steam is a lot less dense than air so it goes up the can and pushes all air out eventually. In this state there is only stem in the can and when it is put into cold water, the steam condenses and makes the inside of the can a low pressure region. Outside air had higher pressure than the inside of the can so it pushes the can from all directions and this external atmospheric pressure implodes the can. During the low pressure some water from the bowl goes into the can through the opening of the can, but this water cannot flow into the can fast enough to fill the can before atmospheric pressure implodes it.