Simple Kids Science Fair Project Idea

You can use Charles Law to show a physicalWhen you cook the soap there is a physical
change in an ordinary bar of Ivory soap.change but no chemical change. It is still soap. This
Charles Law states that a gas based material hasis also why Charles Law is shown because the
a constant pressure and if the temperaturevolume of gas increase as the temperature
increases so will the gas and if a bar of soap isincreases. The microwaves from your oven
made of foam this should cause the foam toexcite the energy molecules in the soap and
increase in size because it is made of cell basedcause them to move very fast and when they
gas molecules and will also increase in size.do this they move away from each other as
Let us look at this before we proceed.they bounce off each other.
Soap is a foam. Foam can be any material thatIf you try another brand of soap, you will
has trapped gas inside of it, somewhat like tinyprobably find that it puffs some but basically
bubbles. You may not think of soap as a foammelts because many other soaps do not contain
because it is solid and hard but foam can come inthe same amount of air. I do not recommend
many forms and they can be solid, hard or softcooking another kind of soap as some have lots
and spongy. You probably think of whippedof perfumes that have strong odors when they
topping as a foam as well as foam you use toare being cooked.
shave.This is why a bar of Ivory soap will float
We are going to test increasing the temperaturecompared to other brands of soap. It has more
on a bar of Ivory soap to see if the gas inside ofair whipped into its preparation and just like a kid
the foam will cause the soap to expand andwith a float on their arms full of air that causes
cause a physical change.them to float in a swimming pool, a bar of Ivory
Here is what we need.soap will float because it has lots of air packed
1.A bar of Ivory Soapinside. Test another brand of soap to see if it will
2.A paper platefloat. Now cut the Ivory soap in half and look at it.
3.Another bar of soap; not IvoryDo you see the little holes of air? Look at another
Now unwrap the Ivory soap and place on thebar of soap after cutting in half.
paper plate.When doing this science project:
Microwave the soap and watch it closely while it is1.
cooking to see what happens.Stay at the microwave and do not leave it
Your soap should finish cooking in 1 to 2 minutes.unattended.
This all depends on the temperature of your2.
microwave. If you cook it too long the soap willDo not put metal items in the microwave
not get any bigger.3.
Let the soap cool off before removing it orThis will not hurt your microwave or the soap.
touching it. You may want a parent to help youYou can still use the soap when done.
with this so no one gets burned.4.
After the soap is cool touch it and examine it.You will notice an odor from the soap as it is
The soap it flaky and hard. It is still soap and youcooking. This will make your microwave smell
can wash your hands with some of the flakes.fresh and flowery for a few hours. Only use
Why does this work?Ivory soap.
Well, when you cook the soap it makes it softHere is the formula for Charles Lawwhere:
and you are boiling the water and gas that isV is the volume of the gas
whipped inside of the soap. When you boil water itT is the temperature of the gas (measured in
evaporates and as it heats also expands. WhenKelvins)k is a constant.
water turns to gas it expands and this causes theV = Vo(1 + ??)
soft portions of the soap to also expand andTherefore, as temperature increases, the volume
makes it now actually look like a foam.of the gas increases.