The Cat in the Hat
Teacher Instructions
(First – Third Grade)
This set of experiments explores density, surface tension and miscibility. Students
are asked to help the Cat in the Hat complete multiple tasks including creating a new hat,
solving a mystery and helping the fish spice up his bowl! This experiment is set up in 3
sections so that it can be split up over a few days or done all at once.
Density is the comparison of mass to volume or the weight of an object compared to how
big it is.
Surface Tension is the force liquid molecules exert on one another creating a tightly
stretched skin across the surface, which allows for things like water bugs to walk on water!
Miscibility is the ability of two substances to mix.
Total time: 1 Hour
Materials per Group:
5 plastic bowls
¼ cup of skim milk
¼ cup of 1% milk
¼ cup of whole milk
¼ cup of half and half
2 different colors of food coloring
1 dish of dish soap
5 Q-tips
¼ cup of corn syrup
1 cup of oil
3 cups of water
2 teaspoons of baking soda
¼ cup of vinegar
1 dropper
1 Fork
5 large clear plastic cups
The Cat in the Hat – Kayla Erf January 15, 2011 1
Instructions:
1. Divide kids into groups of 5
2. For Section 1 give each group:
Corn syrup
Oil
Water
Baking Soda
Vinegar
Food Coloring
2 clear plastic cups
3. Follow this procedure:
1. Pour corn syrup into a clear plastic cup
2. Add 3 drops of food coloring and mix well
3. Sprinkle about 2 teaspoons of baking soda on top of the corn syrup
4. Pour ¼ cup of water on top of the baking soda so that the depth is about ½ inch
5. Pour ¼ cup of oil into the cup so that the depth is about ½ inch
6. In a separate cup mix vinegar and 3 drops of a different food coloring
7. Use a pipette to drop vinegar into the top of the cup
8. Refill the pipette and put it down towards the bottom of the cup to release the
vinegar
4. Have the students fill out the worksheet as they do their experiments
5. Explain that:
● Each different liquid has a different density those with lower densities can
float on top of those with higher densities. Gasses have lower densities than
liquids and that is the reason that the bubbles float to the surface.
6. For Section 2 give each group:
5 Petri Dishes
¼ cup of Skim Milk
¼ cup of 1% Milk
¼ cup of Whole Milk
¼ cup of Half and Half
1 box Food Coloring
1 dish of Dish soap
5 Q-tips
7. Follow this procedure:
1. Pour enough water into a cat dish to cover the bottom.
2. Add 2 drops of blue food coloring to the dish.
3. Dip a Q-tip into the bowl of dish soap
4. Touch the surface of the water with the soapy Q-tip
5. Line up 4 cat milk dishes and label them (Half & Half, Whole, 1%, and Skim).
6. Add 2 drops of blue and two drops of green food coloring to each one
7. Dip a Q-tip in a cup of soap
8. Lightly touch a Q-tip to the surface of each dish of milk
8. Have the students fill out the worksheet as they do their experiments
9. Explain that
● Food coloring is less dense than milk but more dense than water. Therefore
The Cat in the Hat – Kayla Erf January 15, 2011 2
it mixes with the water whereas it sits on top of the milk. As the fat content
goes up so does the density so the food coloring stays more condensed.
However when you add the soap it breaks the surface tension of the milk
and so the food coloring mixes with the milk and looks tie-dyed.
10. For Section 3 give each group:
3 plastic cups
1 cup of water
2 tablespoons of oil
Food coloring
A Fork
11. Follow this procedure
1. 1. Fill 2 cups full of room temperature water
2. Add 2 different colored drops of food coloring to one cup, stir the mixture with a
fork
3. In a dry cup pour 2 Tablespoons of oil and add one drop of 2 different food
colors
4. Stir the oil mixture with a fork
5. Add the oil and food coloring to the cup of clear water
12. Explain that:
● Oil and food coloring don’t mix, but water and food coloring do so when you
add the oil and food coloring to the water the food coloring meets the water
and bursts like fireworks!
References:
Fireworks in a Glass, http://chemistry.about.com/od/4thofjulychemistry/a/waterfireworks.htm,
January 17, 2012
Bubbling Density Concoction, http://www.stevespanglerscience.com/experiment/00000146,
January 17, 2012
Color Symphony, http://www.sciencebob.com/experiments/colorsymphony.php, January 17, 2012
The Cat in the Hat – Kayla Erf January 15, 2011 3
Student Instructions
The Cat in the Hat
(1st – 3rd Grade)
Name: ____________________________________
Date: __________________________
The Cat in the Hat loves playing fun games
But today he needs help to achieve his new aims!
He loves his old hat with its red and white stripes
But he wants your ideas, to create a neat new type!
Use these new words and goopy globs galore
To design a new hat that the Cat will adore!
Do you have a favorite kind of milk? Cause I do!
And the Cat in the Hat, well of course he does too!
Each day he drinks from a big silver bowl
But today it’s too thick! It might even be whole!
The Cat in the Hat is a big fan of skim
So today we will solve a mystery for him!
He loves his milk and his new hat
But do you know what else pleases this cat?
He loves to make mischief! It’s his favorite thing.
But at the end of the day his fish is never laughing!
He’s tried to impress the Fish in the Bowl
But he knows that he needs to be more colorful!
The Cat in the Hat – Kayla Erf January 15, 2011 4
Key Words:
Density is the proportion of the mass (or weight) of an item divided by its volume,
or the amount of space that it takes up. Density is important because it determines
whether an object will sink or float. All states of matter have density!
Surface tension is like a skin that is stretched very tightly across the surface of a
liquid, caused by the force liquid molecules exert on one another. This allows for
things like water bugs to glide across the top of a lake.
Miscibility: The ability of two liquids to mix
Immiscibility: The inability of two liquids to mi
Part 1 - The Cat’s New Hat!
In this activity you will use density and chemical reactions to create the perfect new
hat for the Cat!
Procedure:
1. Pour corn syrup into a clear plastic cup
2. Add 3 drops of food coloring and mix well
Is corn syrup: Thin
or
Thick
1. Sprinkle about 2 teaspoons of baking soda on top of the corn syrup
2. Pour ¼ cup of water on top of the baking soda so that the depth is about ½ inch
3. Pour ¼ cup of oil into the cup so that the depth is about ½ inch
Oil sits on top so it is LESS DENSE
or
MORE DENSE than water?
1. In a separate cup mix vinegar and 3 drops of a different food coloring
2. Use a pipette to drop vinegar into the top of the cup
What happens to the vinegar?
1. Refill the pipette and put it down towards the bottom of the cup to release the vinegar
The bubbles rise to the top of the hat because they are the
Least Dense
or
Most Dense
The Cat in the Hat – Kayla Erf January 15, 2011 5
Part 2: Thick Milk
In this experiment you will investigate the thickness of milk using the principles of
surface tension and density to determine which type of milk the Cat in the Hat would like
best. Remember he likes thin milk!
Procedure:
1. Pour enough water into a cat dish to cover the bottom.
2. Add 2 drops of blue food coloring to the dish.
What happens to the food coloring?
Mixes with Water
Stays as a blob
1. Dip a Q-tip into the bowl of dish soap
2. Touch the surface of the water with the soapy Q-tip
Does the soap have an effect?
Yes
No
1. Line up 4 cat milk dishes and label them (Half & Half, Whole, 1%, and Skim).
Which milk is the whitest?
Half and Half
Whole
1%
Skim
Whole
1%
Skim
Which is the most watery?
Half and Half
1. Add 2 drops of blue and two drops of green food coloring to each one
What happens to the food coloring?
Mixes with Water
Stays as a blob
1. Dip a Q-tip in a cup of soap
2. Lightly touch a Q-tip to the surface of each dish of milk
What happens?
The Cat in the Hat – Kayla Erf January 15, 2011 6
The thickest milk has the highest surface tension and density so the food coloring will not
mix with it until you break the surface tension with the soap!
Part 3 – Water Fireworks
The Cat in the Hat has decided to use the principals of miscibility to set off fireworks
in the Fish’s bowl!
Procedure:
1. Fill 2 cups full of room temperature water
2. Add 2 different colored drops of food coloring to one cup, stir the mixture with a
fork
Does the food coloring mix with the water?
Yes
No
1. In a dry cup pour 2 Tablespoons of oil and add one drop of 2 different food colors
2. Stir the oil mixture with a fork until you have lots of tiny droplets.
Does the food coloring mix with the oil?
Yes
No
We know that oil and water don’t mix but that food coloring and water do! What would
happen if you added the oil and food coloring mixture to the second cup of water?
1. Try it! Add the oil and food coloring to the cup of clear water
What happened?
The Cat in the Hat – Kayla Erf January 15, 2011 7