Sunday, October 27, 2013

Homeschool Science

Like a lot of homeschoolers, we do most of our science in the kitchen.  Gunnar and I cooked up this little project together.  Do you know what it is?

Yah, it's a foam - a closed-cell foam.

Here's how we made it:

Much to his delight, Gunnar got to use his new knife (no kitchen knife for him) to cut a chunk off a bar of Ivory soap.  (Must be Ivory - other soaps won't work.)

This, of course, required much cleaning of the blade of the *NEW* knife.

That accomplished, we popped the soap into the microwave and turned it on.

Immediately the soap began to grow!

We had to stop the experiment, midway, to scoop the soap back onto the plate.
(And I hope you appreciate that I'm keeping it real here... IOW, yes, I know the micro needs to be cleaned.  Badly.)

The soap maxed out its size in about a minute.

When we heated the soap it softened and became more pliable.  The air and water trapped inside the soap were also heated.  The water vaporized and expanded, causing the soap to expand and become a foam.  The finished product - the foam - cooled, shrinking slightly, and became firmer again.

Science nerd question - 
was this a physical change or a chemical change?

Always the funny guy, Gunnar wanted to save the foam and trick his brothers ;D


sara said...

pretty sure that's a physical change. It's still soap, right? Now the actual act of saponification baffles me - is that physical or chemical? Also, I have come *this close* over the past couple of years to buying a microwave just so I could do that.

Joyful Reader said...

that is really cool! It looked like whipped topping or something!

Abi's Blog said...

My grandkids LOVED this...we added drops of food color then watched the different colors blend. We need to do it again!

Herding Grasshoppers said...

Sara - I bet there's a microwave at your church? A friend's house? Even if the soap overflows off the plate, it's easy to clean up.

J.R. - It DOES look like whipped topping! Like the top of a meringue pie?

And Abi, food coloring! Great idea! We'll have to do it again!

Herding Grasshoppers said...

And - yes - it's a physical change. No chemical reaction has taken place. It's still soap. You can break off a piece, lather up, and wash your hands. :D

sara said...

We've only been here about a year, but I think it's time my new friends really got to know me - I'm going traveling with a bar of Ivory. :)