Generating trapped heat!
When you use a match to light a candle, both give off heat and light. But where did that heat actually come from? This experiment will show that heat doesn't always need a flame and bright light. In fact, there is a little bit of stored energy, or potential heat, trapped inside pretty much everything around us. It’s just waiting to be set free.
Materials Needed
- Fine steel wool with no soap
- White Vinegar
- Two disposable cups
- Latex gloves & goggles
- Copy paper
- Hole puncher
- Thermometer
- Fold the paper in half and punch a hole as close to the middle as possible. Set it aside.
- Put the gloves on. Separate some of the steel wool and place it in one of the cups.
- Pour a few tablespoons of vinegar into the steel wool and let it soak in for about a minute.
- After a minute, remove the steel wool, and shake out the vinegar over the sink.
5. Wrap the steel wool around the base of the thermometer and place it in the clean cup.
6. Place the paper over the cup, making sure the thermometer shows through the hole.
7. Take note of the temperature and then observe it for five minutes before recording the final temperature number.
Observation
What did you notice during those five minutes?
The Science
You should have observed the temperature rising and the steel wool starting to get rusty. Here’s what happened: Things like steel wool are held together by chemical bonds which need energy to stay together. But they are stored under some 'pressure,' like people having a tug-of-war.
The vinegar helps break some of those bonds, acting like a little helper to weaken the 'grip.' The iron atoms rush to combine with oxygen from the air. They form a highly stable new compound (rust). When the stored energy moves into this new, tighter arrangement, the 'extra' energy is released. This release is known as an exothermic reaction, which is why the temperature went up during our observation time.
