Ivory Soap Experiment

Description

The Ivory Soap Experiment is a fun one for kids. Let them predict whether different brands of bars soap will sink or float in a container of water. Then microwave the "one that floats" and watch what happens! It will expand 6x its original size into a fluffy cloud. Great way to introduce the ideas of solids and gasses.

Here is our experiment for you to view:

Materials

1 FRESH bar of Ivory Soap
1 Bar of Dove Soap or other brand
Clear Container filled with water. You could use a pitcher, vase or a large measuring cup.
Tongs or Slotted Spoon to retrieve the soap.
Large microwave safe plate
Microwave Oven

Steps

let the children examine both bars of soap.
Have them predict whether each soap will float or sink and why they think a particular one will sink or float.
Place one bar of soap at a time in your container of water to see what happens.
Discuss why one might float and the other sink.
Dry the soap with a paper towel. Cut the Ivory Soap into quarters. (Adult Step)
Examine the pieces of soap. Do you see any air pockets or does it look solid?
Place the quarters on microwave safe plate.
Microwave for 60 seconds.
Remove from microwave. The soap will be warm, not hot.
Let cool slightly for children to touch.
Place pieces of the Ivory soap on a small dish or bowl for children to wash hands with...it will be very flaky or put in a small mesh bag.

Tips and Suggestions

If you have a 1,000 watt or higher microwave, try setting it for 60 seconds first.
Be sure to use a fresh bar...one that has been stored on a shelf may not be as effective.
If you want to use the soap, save a netted bag from garlic, scallions or little boiler onions and place soap inside!
Make sure children wash hands after handling so they don't rub their eyes and get them irritated.
Do not leave soap unattended while microwaving. Extra time in the microwave should not cause any melting or damage but you should always monitor anything you put in the microwave.
Note that your microwave will be very fragrant for a couple days.

Educational Notes

What is Happening? Heating the Ivory soap softens it and heats the air and water trapped within the bar of soap. This causes the water to vaporize and the air to expand. The expanding gasses push on the softened soap which causes the soap to expand. The appearance of the soap is changed however no chemical reaction is occurring.
Ivory bar soap is whipped with air in its production and that is why it floats in water. Ivory's first slogan "It Floats!" was introduced in 1891. Other brands of soap do not have as much air in it and will not have the same result. We did not test any other brands in the microwave.