The JumpStart Blog

Does OJ complete your breakfast too?  Orange juice really has some neat properties besides being refreshing.  It’s available, it’s sweet, and it’s packed with Vitamin C. But, have you tried OJ frozen before?  This experiment will give you and your child the chance to give it a taste, and to compare and contrast straight ice against frozen orange juice.  You’ll be able to see the differences between frozen liquids with and without dissolved sugars in them.  Also, your child will likely be thrilled to sample frozen orange juice!

SnO-J-flakes

Materials:

• Two Styrofoam or plastic cups
• Water
• Orange Juice
• Freezer
• Spoon

Directions:

1. Fill one of the cups with water, the other with orange juice.
2. Put them in the freezer, let them freeze thoroughly over a few hours.
3. Once they’ve frozen, take a look.  The water is frozen ice, and the OJ is frozen, but it has a sticky sort of unfrozen syrup on top.


See the syrup hanging around the cup's rim?

4. Let both sit for 5 minutes.
5. Take the spoon and try scraping off some of the ice and then some of the juice; taste the juice scrapings you can get off.



6. Continue to scrape at the frozen juice and water every so often.  You’ll begin to notice a difference.

Weren’t the juice scrapings good?

As you continued scraping and the cups began to warm, you probably noticed that the juice came apart easier, separating into small, flat crystals.

Tasty.

Why is this?

Dissolving substances like sugar in water lowers water’s freezing point so that it must be colder to freeze. As the juice gets colder, some of the water in it begins to freeze.

The amount of dissolved sugar stays constant, but there is less and less water as it is taken up in the growing ice crystals.  The juice sugar ends up trapped between them.  The sugar acts as separations in the frozen water, and lets the ice crystals come loose easily, when you scrape at them.

With the pure water that you froze, the crystals were unified, making one solid block of ice with no separations created by other substances among the crystals.  When the frozen water cup warmed up, the exposed surface melts, but the rest stays solid. It does not come apart like the OJ did.

You’ve probably noticed a similar syrupy coating on your popsicles.  The same concept applies here!  Hope you enjoyed your ice scrapings!

Like this simple experiment?  Share it with friends.