Thursday, February 16, 2012

Hands on Science - Expanding Soap

A week or two ago Dad sent a link for a project he thought Doodle Bug might like.  Usually these projects are hands on and fun and can be tied into what we are learning about at the time.  Sure enough, it was cool, but on further inspection it's more a chemistry unit than a life science one (although to his credit it did talk about cells).  But, being the lovers of hands on science that we are that didn't stop us (c: 


I made a recording sheet to go with our experiments and you are welcome to use it if you like. (c:  So, the first step is to get your recording sheet and a pencil ready. 


The next step is to gather your supplies.  For the entire process you will need a bar of Ivory soap (yes, you have to use that brand) and a bar of some other soap (we used lever because it's the only bar soap we had on hand); two microwave safe (as in glass, read on to find out why) bowls, a large container for water (or just use your sink if you like) and a butter knife or something similar to help break the soap.


Observe the soaps on the outside.  Compare their physical characteristics (if you have a kitchen scale weigh them, we didn't) - use your senses (except taste, please don't eat the soap).  Now break the soaps open to compare them on the inside.  We had to use a butter knife to start the breaking process.  Don't cut all the way through, though, you need that broken edge to be able to really see the insides.  In our photo above the Ivory soap is on the left and the Lever is on the right.  We noticed small air pockets in the Ivory while the Lever looked like rock layers.


Next, you will want to see what happens when you put the two soaps in water. Make predictions - what do you think will happen when you put the soaps in water?  Fill your container (we used a large tupperware-type bowl, but you can use whatever you like) with water and place the soaps in.  Go ahead and use the broken pieces, it won't effect the outcome at all.



Now for the amazing part of the experiment.  It's time to microwave the soap!  Place a sample of each soap in a microwave safe bowl.  Microwave on high for 1-2 minutes.  You will see that the Ivory soap has a much better reaction to microwaving than the Lever soap.  Caution: That steaming pile of soap is hot - don't touch it or it might burn you. 



When you take the soap from the microwave it will quickly loose it's fluff factor.  You can use this as a discussion point of why this happens - and why the soap fluffs at all.  (Hint: those air pockets trap steam and steam is a magically thing.)


Want to know why you can't use a plastic bowl with the Lever soap?  See that bowl?  When we started this experiment it didn't resemble the surface of Mars quite so much as it does now.  Yeah, microwave safe means glass, my friends.  Also, it's important to note that the Lever bar stunk to high heavens when we microwaved it (yes, I do realize that some of that smell was burning plastic).  We had the window open, the vent fan on and a couple of candles burning to help make the kitchen smell not so much like a chemical facility.  The Ivory soap on the other hand, just smelled strongly like Ivory soap. 


So, in summing things up, you can compare the final product of the two soaps from this experiment.  All of that fluff is from just under one bar of Ivory soap (some of our fluff is permanently embedded into my kitchen rug).  The Lever bar (and it's bowl) are in a freezer bag because, well, they just stunk so bad.  Both soaps are still usable after the experiment is over. In fact, if you have little ones, the Ivory soap flakes would make an awesome sensory tub filler.

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