Ice Cream

Chemistry | 20-30 min.

In this activity, kids learn about freezing, liquid properties, and treats!

Materials Needed

Per Student:

• ⅓ cup half and half

• ½ tsp vanilla extract

• 1 Tbsp sugar

• 1 sandwich sized zip-top bag

• 1 spoon

Per Two Students:

• 2 gallon sized zip-top bags

• 6-8 cups of ice

• ½ cup salt

A Few Per Group:

• ⅓ cup measuring cup

• ½ cup measuring cup

• ½ tsp measuring spoon

• 1 Tbsp measuring spoon

Optional:

• Flavored syrup

• Sprinkles

• Chocolate chips

• Other ice cream mix-ins

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Steps:

1. Partner up the students

2. Have each student write his or her name on a sandwich bag.

3. Have each pair write “Salt” on one gallon bag and “No Salt” on the other

4. In the sandwich bags, have each partner combine…

• ⅓ cup half and half

• 1 tsp vanilla extract

• 1 Tbsp sugar

• Any extra mix-ins

5. Seal bags and set aside.

6. Have each pair put 3-4 cups of ice and ½ cup salt in one of the gallon bags.

7. Have each pair put 3-4 cups of ice without salt in the other gallon bag.

8. Put one prepared sandwich bag in each gallon bag.

9. Have each student shake one of the plastic bags for 5 min.

10. After 5 min. of shaking, have students remove the two sandwich bags and observe the differences.

• Does one feel colder than the other?

• Do the ice cubes in one bag look different than the others?

• The sandwich bag in the bag with salt should be closer to frozen than the other.

11. If either bag looks ready to eat, enjoy! If they need a little more freezing time, place them in the bag WITH ice and shake until delicious.

Explanation:

Salt lowers the temperature at which water freezes (freezing point). That means that ice can turn to water without getting warmer!

Real World:

The saltwater oceans don’t freeze very easily. When it gets really cold outside, ponds, lakes, and puddles freeze over, but it has to get really REALLY cold before the ocean will. That’s because the same thing is happening in the water as it did in our ice cream bags!