Science Buddies: "Ask an Expert"

Hello everbody,
I need to understand my results for my experiment. My project is Supercooling water and Snap Freezing. I used all the water and boiled them but the Tap water always came the lowest and fastest to come to the negative area. Can you help understand why this is?









Thanks,
quangnguyen

Hello:

I'm not sure I understand your question about boiling the water, but I do see that as one variation mentioned in the experiment. The main experiment is to supercool distilled water. Tap water will probably not supercool very much, but distilled water should go down to -3 C. It sounds like your results for plain tap water vs. tap water that was boiled are that the tap water will supercool more than the boiled water. Depending on how long you boiled the water, it may have a higher concentration of impurities, and that would explain why it does not supercool as far.

I will answer your questions about salt in a response to your other posting.

Keith