Freezing Water Experiment

Supplies needed:

1)      4 clear, plastic glasses

2)      4 wide straws

3)      Water

4)      Thermometer

5)      Freezers

Experiment design:

1)      Measure ½ cup of water into each glass

2)      Measure each depth

3)      Add salt

a.       Control – no salt

b.      ½ tsp

c.       1 tsp

d.      2 tsp

4)      Measure each depth

5)      Take each temperature

6)      Place straw in glass

7)      Measure each depth

8)      Place in freezer (same general location)

9)      Every 20 min take temperature again and record

Hypothesis:

·         The more salt in each glass, the longer it shall take to freeze. From my prior knowledge I understand that salt lowers the boiling temperature of water, therefore I believe it shall also lower the freezing temperature.

Results:

·         The control froze at approximately 0^o Celsius

·         The more salt added to the water did lower the freezing temperature I found that just a little bit of salt did affect it, while adding 4 times as much barely did more than the ½ tsp.

·         Therefore my hypothesis was half true. It did lower the boiling point, but only to a certain point.
After the time I alloted (100min), The control had a layer of ice aross the top (very thin), while the others had about a half inch of "slush" across the top.