Ice Cream in a Bag!Ice Cream in a Bag!

Estimated Time: 40 minEstimated Time: 40 min

Grade Level: 8-9Grade Level: 8-9

Subject: Introductory ChemistrySubject: Introductory Chemistry

Getting StartedGetting Started

Is the making of ice cream chemistry?Is the making of ice cream chemistry?

What ingredients are in ice cream?What ingredients are in ice cream?

Today we are going to do an experiment Today we are going to do an experiment on the science of making ice cream.on the science of making ice cream.

Work in pairs!Work in pairs!

Materials (per pair)Materials (per pair)

1 qt. resealable bag1 qt. resealable bag

1 gallon resealable bag1 gallon resealable bag

½ c. sugar½ c. sugar

1 c. milk1 c. milk

1 c. whipping cream1 c. whipping cream

½ tsp. vanilla½ tsp. vanilla

½ c. rock salt½ c. rock salt

12 ice cubes12 ice cubes

winter gloves or winter gloves or mittensmittens

2 plastic cups2 plastic cups

2 plastic spoons2 plastic spoons

Procedure (1)Procedure (1)

1. Add the sugar, milk, whipping cream, 1. Add the sugar, milk, whipping cream, and vanilla to the quart bag. Make sure and vanilla to the quart bag. Make sure the bag is completely sealed with as little the bag is completely sealed with as little air inside as possible.air inside as possible.

2. Add the rock salt and ice cubes to the 2. Add the rock salt and ice cubes to the gallon bag.gallon bag.

Procedure (2)Procedure (2)

3. Place the sealed quart bag into the 3. Place the sealed quart bag into the gallon bag and then seal the gallon bag. gallon bag and then seal the gallon bag. Again, make sure the bag is completely Again, make sure the bag is completely sealed with as little air inside as possible.sealed with as little air inside as possible.

4. Put your gloves or mittens on… our goal 4. Put your gloves or mittens on… our goal is to freeze the ice cream, not your hands!is to freeze the ice cream, not your hands!

Procedure (3)Procedure (3)

5. 5. GentlyGently shake the bag so that the ice is shake the bag so that the ice is continually moved around the milk mixture.continually moved around the milk mixture.

6. When the milk mixture is frozen, take 6. When the milk mixture is frozen, take the quart bag out of the gallon bag and the quart bag out of the gallon bag and wipe it off with a paper towel. Pour the wipe it off with a paper towel. Pour the ice/salt mixture from the gallon bag into ice/salt mixture from the gallon bag into the sink.the sink.

Procedure (4)Procedure (4)

7. Distribute the ice cream7. Distribute the ice cream

evenly between your two cups andevenly between your two cups and

enjoy your treat while you answerenjoy your treat while you answer

the following questions…the following questions…

Please remember to clean up your area Please remember to clean up your area after you are finished!after you are finished!

Questions (1)Questions (1)

1. How many phase changes did you 1. How many phase changes did you observe in this experiment?observe in this experiment?

2. What would happen if you didn’t2. What would happen if you didn’t

add salt to the experiment?add salt to the experiment?

3. What happened to the ice in the outside 3. What happened to the ice in the outside bag? Why?bag? Why?

Questions (2)Questions (2)

4. Why do some people sprinkle salt on icy 4. Why do some people sprinkle salt on icy sidewalks?sidewalks?

5. List a question you thought of during 5. List a question you thought of during this experiment and describe a procedure this experiment and describe a procedure that you could do to answer the question.that you could do to answer the question.

Clean-Up!Clean-Up!

Please leave your workspace as Please leave your workspace as clean or cleaner than you found it!clean or cleaner than you found it!