Chemistry 2014
Ice Cream Lab
Purpose: To Investigate –
• The effects of heat transfer on phase changes.
• The effects of temperature changes on physical changes
Materials:
240 mL milk
35 g sugar
100 g rock salt
2.5 g vanilla flavoring
Ice
towel or gloves
3.8 L & 0.95 L ziplock bags
Procedure:
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Place a towel over your work area. Keep your experiment on the towel.
Pour the 240 mL milk, 35 g sugar and 2.5 g vanilla flavoring into the .95 L ziplock bag.
Carefully seal the 0.95 L ziplock bag and shake the mixture thoroughly.
Put the sealed bag into the larger 3.8 L ziplock bag.
Add roughly 750 mL of ice to fill the remaining space in the 3.8 L ziplock. Then add 100 g of rock
salt. Be sure to leave enough room to seal the ziplock.
If you have gloves, put them on. You are 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. It should take 20-25 minutes to freeze.
Dish out the ice cream for one student to eat out of the bag, the other the cup)
Clean up your lab area and hang any damp towels on the front cart.
Analysis:
1) What state of matter was the milk in before and after the lab?
2) What happened to the heat energy that left the milk?
3) Why was salt added to the ice?
4) If you did not add sugar, would the ice cream have frozen faster? Explain?
5) Why did the outside of the bag get wet? (Assume that your bag did not spring a leak)
6) Why is salt spread on roads after a winter storm?
Chemistry 2014