Ice cream by zhangyun


									Ice cream lab

Changes in state,
 Energy transfer
Hand crank ice cream maker
               Big question
• How does the change in energy within an
  object affect its state of matter?
Need 4-5 volunteers
           Set-up for Ice Cream
• Location of supplies

• Volunteers to run stations

• Clean-up and throwing away of trash

• In case of Spills…

• If you do not like or can not eat ice cream…
        Equipments and ingredients
•   2 tablespoons of sugar
•   1/2 cup of milk
•   a few drops of vanilla or other extract for flavor.
•   zip-lock sandwich bag
•   1 gallon zip-lock freezer bag
•   Lots of ice cubes,
•   2 tablespoons of rock(kosher) salt.
•   Towels!
•   Gloves!
         Steps for making Ice Cream
• In a small plastic bag, pour
   – ½ cup of milk
   – 2 tablespoons of sugar
   – 3-4 drops of vanilla
• Seal Bag without air.
• Obtain a second, larger (gallon) plastic bag.
• Place 3 large cups of ice into gallon bag.
• Bury the smaller milk filled bag in the ice of the larger bag
• Add 2 tablespoons of Kosher or rock salt to the ice in the
  larger bag. Close up gallon bag.
• Begin to massage the bag
            Making Ice Cream
• Gently massage the components together for
  5-10 minutes.

• The bag will get VERY COLD. Use a towel , or
  insulated gloves

• Ice cream is ready when mixture feels like clay,
  with grit
          Eating the Ice Cream
• Open outer bag carefully , try to save bag.
• Dump ice-salt water mix into indicated trash
• Open inner bags with scissors or by hand. Try
  not to let salt-water mix get to ice cream
• With spoon ,transfer ice cream to cup
• Remember administrators and teachers like
  ice cream too!
After making and eating the ice-cream
Answer Questions based on Ice Cream Lab
     Ice Cream lab questions
1.    If ice cubes are put into a drink, how come the drink
      does not freeze?

2.    Name 3 specific endothermic changes that occurred
      during the lab

3.    Name 3 specific exothermic changes that occurred in
      the lab
4.    Explain in terms of energy, why the milk mixture turned into ice cream.

5.    If you repeated the lab set-up, but did not spend time massaging the
      bags, what result would you expect. Explain why, in terms of energy

6.    What was the purpose of the salt? Explain your answer in terms of

       I AM NOT YOUR

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