Ivory Soap Science Experiment 4th Grade

BIG QUESTION: Why does a bar of Ivory soap expand in the microwave?

HYPOTHESIS: I think that the bar of Ivory soap (when it’s put in the microwave) will change shape and bubble up.

Interesting Research Facts: Soap smell fills the room when it gets hot. There are a lot of websites with great science experiments. Research is fun All soap is not the same

Experiment: Materials: 1 - Bar of Ivory soap 2 - Other bars of soap 1 - Deep bowl of water 1 - Roll of paper towels 1 - Microwave oven

SOAP… NOW THAT’S FUNNY!

Details: 1. Fill the bowl with water. 2. Drop the bars of soap in the bowl of water. Watch those bars of soap and what happens compared to the bar of Ivory soap. 3. Remove the bar of Ivory soap from the water and break it in half.

Details (cont): 4. Place the half bar of Ivory soap on a paper towel and put it in the middle of the microwave oven. 5. Cook the bar of soap on HIGH for 2 minutes. Keep watching the soap and watch it expand and bubble up into a big soapy blob. 6. Allow the soap to cool before touching it!

Control/Variables: 1. We used the same microwave oven for each bar of soap. 2. Each experiment was timed the same. 3. The power setting on the microwave was set at high for each test.

Observations: Ivory soap is the only soap with air bubbles inside. The soap expanded in the microwave. It floats in water and others don’t. It didn’t explode in the microwave.

DATA: The Ivory soap floats in the water and the other bars of soap drop to the bottom of the bowl. The Ivory soap is less dense than the water. It floats because it has air mixed into it when it is made in the factory.

ANALYSIS OF DATA: a. The experiment tested our hypothesis. The bar of Ivory soap expanded in the microwave when we cooked it on HIGH for 2 minutes. The other brands of soap did not. b. Ivory had air and water inside of the bar soap so it reacts to the heating process in the microwave. It expanded because the water built up bubbles from the heat and boiled up to create a blob of soap.

CONCLUSION: a. Yes, my hypothesis was correct. I thought the bar of soap would expand and change shape but I didn’t really know why it would until I did the whole experiment. Then I found out the air and water caused it to expand because that was the reaction when the bar of Ivory was heated in the microwave. The Charles’ Law says, “that as the temperature of a gas increases so does its volume.” It was pretty cool to see.

CONCLUSION: b. I would like to try the experiment with more brands of soap to see if any other brands would react the same way or do something really different like evaporate! c. Would the Ivory soap still expand if I did not put it in water first? Does any other brand of soap have that much air in it? Would the bubbles get bigger if it stayed in the water longer?

References: Making Science Fun! http://www.stevespanglerscience.com/experiment/00000053 © 2010, Steve Spangler Science http://yourfunfamily.com/Science/ivorysoap.html © 2010, Your Fun Family

THE END! THAT WAS FUN!!!