Ivory’s first slogan, “It Floats!”, was introduced in 1891.
Ivory bar soap is whipped with air in its production and floats in water. 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.
When Ivory soap is heated in a microwave it gets hot and causes the soap to get soft. The microwaves beaming in the oven excite the water and air molecules inside the soap cause them to move in opposite directions from each other and vaporize. The vaporization of these molecules causes the tiny air pockets or bubbles trapped inside the soap to rapidly expand.
Since the soap has been heated and is in a soft state, the expanding air and water molecules can easily push it out into a new foam like substance.
Although the soap looks different from when we started, but it remains the same. However no chemical reaction is occurring. What did occur was a demonstration of Charles’ Law the volume of gas increases with temperature.