| MadSci Network: Chemistry | 
The September 1995 SCIENCE SCOPE magazine described a demonstration 
experiment in which one regular-sized bar of Ivory Soap was placed in 
a microwave oven for two minutes.  The soap forms a rigid, irregular, 
"cumulus" extrusion approximately 3X in size.  Ivory provides a more 
dramatic effect compared to other brands.
Proctor and Gamble advertises Ivory Soap to be 99-44/100% pure.  It 
contains vegetable oils, animal fats, fragrance and, of course, the 
whipped air that provides its famous buoyancy ("The soap that 
floats!").
Re: Why does Ivory soap expand in a microwave oven?
Try the links in the MadSci Library for more information on Chemistry. MadSci Home