Put this small zipper bag inside the larger 3.8 L zipper bag.
In the 3.8 L bag add enough ice to cover the 0.95 L bag and add 80 mL of salt. Take the temperature of the ice:______ C
CAREFULLY SEAL THE BAG!
Put your gloves on and get ready to make a phase change!
Take turns flipping the bag. Hold the bag by its corners. Keep the bag flipping over and over. Remember to keep the bag over the towel at all times. It should take 10 to 15 minutes to freeze. Take the temperature of the ice/water mixture again: ________ C
When you have ice cream, take the smaller bag out and rinse it off with cold water. It is important to get all of the salt out of the seal area to avoid the salt tainting the ice cream. One partner needs to take the larger bag and its contents to the trash bag. DO NOT DUMP IT DOWN THE SINK!!!
Share the ice cream equally and ENJOY!
Answer the following in the conclusion of your lab report:
What state of matter was the milk when you began?
What state of matter was the milk when you were done?
In order to change the phase of the milk, what had to be removed?
What happened to the heat energy that left the milk? What type of reaction is this?
Why was the salt added to the ice?
If you did not add sugar would the ice cream have frozen faster? Why?
Why did the outside of the bag get wet? (Assume that your bag did not spring a leak.) What states of matter were involved in this process?
Adapted from UVA Physics Department