20 Minute Labs - Super Sized Gummy Bears

MAKE SOME GIANT GUMMY BEARS!

In this month's 20 Minute Lab, we're going to see what happens when we submerge gummy bears in different liquids and solutions. We chose six different liquids to try, but you don't have to stick to those - you can choose any liquids you have around your house that you want to test!

Safety Warning: Don't eat the experimental gummy bears! They will taste gross and also might have bacteria from being handled, soaked, and left out. Set aside some regular gummy bears for snacking!

• 
  gummy bears (set aside some for snacking!)
• waterproof mat and white chalk (or pen and paper - it's just messier! We used the mat from Yellow Scope's Foundation Chemistry kit)
• 6 small glasses
• 1 1/2 cup water
• 1 tablespoon salt
• 1 tablespoon baking soda
• 1/2 cup milk
• 1 tablespoon pineapple juice (or any 100% fruit juice)
• 1/2 cup vinegar
• 1/2 cup measuring cup
• tablespoon
• regular spoon
• napkins

LET'S GET STARTED!

1. Set up your glasses and mat and label six sections with chalk like this:
   
   
2. 
   Fill the tap water glass with 1/2 cup of tap water.
   
   
3. To the baking soda glass, add 1 tablespoon baking soda and 1/2 cup of water. Stir until well mixed (it may not dissolve well - that's okay)
   
   
4. To the salt glass, add 1 tablespoon salt and 1/2 cup water. Stir until dissolved.
   
   
5. Now add 1/2 cup of milk, 1/2 cup of pineapple juice, and 1/2 cup of vinegar to the three glasses on the right, respectively.
   
   
6. 
   Choose two gummy bears of the same color for each of the six cups. For example, 2 yellow for water, 2 green for salt. One will be the 'experimental' gummy bear, and the other will act as the 'control' bear. The control bear will not be exposed to the experiment conditions, but used later to compare sizes.
   
   
7. Place one gummy bear from each pair into its corresponding glass.
   
   
8. Wait over night (or 12 hours).
   
   
9. 
   One at a time, with your regular spoon, remove each gummy (draining it of liquid as much as possible) and place it on the napkin to dry for a few seconds.
   
   
10. Place the gummy bear next to its control in its section on the mat. Observe the difference in sizes!
    
    
11. Optional: wait another 12 hrs to see if there's even more change!

WHAT'S GOING ON?

1) Why didn't the gummy bears dissolve?

The sugar in candy dissolves easily with water, because the molecules from the sugar are attracted to the molecules of the water, so the sugar breaks up to join the water particles.

In addition to sugar and water, however, gummy bears also contain gelatin. (Gelatin is what makes the bears chewy!) A gummy bear (like other gelatinous candies) has a semi-permeable membrane, meaning the outer layer is a wall-like structure with little holes in it. 

When you submerge a gummy bear in water, the sugar can't get out because sugar molecules are too big to fit through the holes. The gelatin holds the general shape together. Therefore, it doesn't dissolve. To learn more about semi-permeable membranes, try our 20 Minute Lab: Naked Egg, Big Egg, Small Egg.

2) What made the gummy bears change size?

But why did your gummy bear in the plain water get huge? Well, water molecules are smaller, and they CAN move through the semi-permeable membrane to get in or out. Why would water move into the bear and not just stay where it is?

In chemistry, molecules like to move from an area of high concentration to low concentration until there is an equal amount in both areas. This principle is called osmosis.

The Water Bear

Let's think about the experiment with the glass containing just the water. Outside of the bear in the glass, the concentration of water is high. Inside the bear, the concentration of water is lower, because the sugar molecules are trapped inside. So water moves from the glass into the bear. The gummy bear takes in a lot of water and grows very big!

Milk, Juice, and Baking Soda Bears

What about the other liquids you used? Well, you can tell by the size of the resulting bear that a lot of those other solutions had water mixed with something already (baking soda, sugar in the juice, fats and proteins in the milk). Not as much water was needed to balance out both sides, therefore, those bears didn't get as big.

However, there were two exceptions to just plain getting bigger:

The Salt Water Bear

Notice that your bear in the salt water stayed pretty much the same or may have even got smaller! That's because salt molecules are very small, and can move easily through the bear's membrane. So the salt from the glass can move into the bear until the concentration is closer to equal. If you added even more salt to the water, and the concentration would be greater outside of the bear, and water from the bear would be drawn out into the glass. In this case, the bear would shrink in size. Give it a try to see what happens!

The Vinegar Bear

You may have noticed that your vinegar bear grew but also started to fall apart! That's because vinegar is an acid - it slowly starts to break down the gelatin that holds the bear's shape together.

Looking for more candy-based science experiments? Check out these other experiments from our blog page:

• Solar Oven S'mores
• Homemade Rock Candy

SHARE WITH US!

Let us know how your experiments turned out! Share your photos and results with us on Facebook, Twitter, Instagram, or send us an email to info@yellow-scope.com. We love getting your messages!

For more exciting experiments, check out our Yellow Scope science kits on the Shop tab of our website!

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