Mrs Pienaar
Supercooling
Water
Introduction
Supercooling is relevant as it can help us increase the amount of time we can keep an organ outside a body before it is transplanted,
Investigative Question
How long do different types of water take to freeze.
Hypothesis
Tap water will start to freeze as the water reaches just below zero degrees Celsius. Distilled water will last for about 3-4hours in the freezer below zero degrees Celsius without freezing as long as it is not shaken and there are as little as possible impurities in the water when below zero degrees Celsius.
Variables
Independent: amount of time water is left in …show more content…
Controlled: amount of water in the bottles, types of water used
Method
1. a bottle of tap water and distilled water was placed horizontally In the freezer. The bottles all had a 1L capacity.
2. Check on the bottles of water every half an hour to see how much of the water has frozen.(if any)
3. Once the distilled water has gotten below zero (if it has not started to freeze) leave it in for another 30 minutes to 1 hour, then take it out and pour it onto ice or bang it on a hard surface and hopefully you will see it start to freeze.
4. Try the experiment again to see if you get the same results.
Data
Freezing points of tap water vs distilled water
Time in freezer Tap Water Distilled water
30 minutes Water on top and bottom started freezing No ice
1 hour ice grew mainly on bottom No ice
1:30 hours Ice on bottom grew to 1cm No ice
2 hours Ice on bottom grew to 2cm No ice
2:30 hours Ice on bottom grew to 3cm No ice
3 hours Fully formed ice to 5cm Fully formed ice
Analysis
When the distilled water started to freeze it froze very quickly because the particles now had something to form off of, water froze from the bottom as they were placed directly on the cooling