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Q & A: Is tap water different from distilled water?

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Most recent answer: 01/02/2013
Q:
I don't know if this counts as a homework question but for my science fair project I'm doing boiling points of mixtures (like water and sugar)but if i did tap water would it be different because I want my data to be accurate. And any way why is tap water water is different from fresh water?
- Zaynab (age 11)
Hollywood,Florida,United states
A:
I'm not positive what "fresh water" means here. Here are some thoughts about how you could tell if tap water is different from, say, distilled water, besides measuring the boiling point.

1. You could taste them to see if they taste different.

2. You could dry out a glass of each and see if anything different is left in the glass.

3. You could compare how they read on a pH meter or maybe just on some litmus paper.

4. You might be able to compare the electrical conductivities if you have the right type of meter. If not, maybe you could use an ordinary ohmeter and measure the resistance across the probes (NOT PLUGGED INTO THE WALL) of the type of humidifier that runs electrical current through the water to boil it. Of course you'd need to make sure that you used the same level for each type of water.

5. You could try measuring the freezing point, although this is tricky because water can be supercooled.

Mike W.



(published on 01/02/2013)

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