Ice Cream Lab
Cayla Cornwell 5/4/14

Objective: Certain substances affect the state of ice. When salt is sprinkled on ice, for example, it causes the ice to melt. This chemical reaction is actually an heat energy transfer. Water freezes at 0 degrees Celsius. A saturated salt water solution freezes at -32 degrees Celsius. What happens if you sprinkle salt on ice?

 Materials:  

1. 

    1/2 cup of milk

2.  1/2 cup whipping cream(heavy cream)

3.  1/4 cup sugar

4. 1/4 teaspoon vanilla or vanilla flavoring (vanillin)

5. 3/4 cup sodium chloride( NaCl) as table salt or rock salt

6. 2 cups ice

7. 1-quart Ziploc bag

8. 1-gallon Ziploc bag

9. Thermometer

10. Measuring cups and spoons

11. cups and spoons for eating you treat 

    
    

      Procedure:https://www.youtube.com/watch?v=hZRCP7wjG4U

    1. Add 1/4 cup sugar,1/2 cup of milk, 1/2 cup whipping cream, and 1/4 teaspoon vanilla to the quart Ziploc bag. Seal the bag securely

    2. Put 2 cups of the ice into the gallon Ziploc bag

    3. Use a thermometer to measure the record the temperature of the ice in the gallon bag

    4. Add 1/2 to 3/4 cup salt (sodium chloride) to the bag f ice

    5. Place the sealed quart bag inside the gallon bag of ice and salt. Seal the bag securely. 

    6. Gently rock the gallon bag from side to side. It's best to hold it by the top seal or to have gloves or a cloth between the bag and your hands because the bag will be cold enough to damage your skin.

    7. Continue to rock the gallon bag for 10-15 minutes or until the contents of the quart bag have solidified into ice cream.

    8. Open the bag and use the thermometer to measure and record the temperature of the ice/salt mixture.

    9. Remove the quart bag, open it, serve the contents into cups with spoons and ENJOY!

        Data:

       1.What kind of ice cream are you making?

       I am making Chocolate ice cream.

       2. Document the temperature of the ice in the gallon bag before adding the salt

       0 degrees Celsius = 32 degrees Fahrenheit  

       3. Document the temperature of the ice/salt mixture (not the ice cream) in the gallon bag when the ice creams starts to solidify

       -10 degrees Fahrenheit

       4. What is the temperature difference before adding the salt and after mixing for 5 minutes?

       -10 degrees

       5. What is the temperature difference before adding the salt and mixing for 10 minutes?

       -5 degrees

     Conclusion Questions:

     1. What kind of chemical reaction is the process of ice cream making, as done in our lab?Explain why.
    The type of chemical reaction that is taking place during this lab is energy transfer. I say this because the salt is reacting to the ice water and casing the ice to melt and become colder which then solidifies the ice cream mixture.
    2.Explain why salt water is harder to freeze than plain water.
    Salt water is harder to freeze than plain water because the sodium chloride cause a heat energy transfer, causing the water to take longer to freeze than plain water.
    3.Is the process of making ice cream a physical or chemical change? Explain your answer.
    The process of creating ice cream is a physical change because the liquid became a solid and could be reversed by melting.
12.  4. Why is salt used with the ice instead of sugar?
    Salt is used with ice instead of sugar because sugar would not create the same energy transfer as the salt.