Sunday, January 10, 2010

Science Sunday - The Effects of Salt on Ice and Boiling Water

I had a germ related experiment in mind for our Science Sunday project, but when the girls noticed the salt on the sidewalk, as we were leaving church today, we switched gears.

When we got home, we found the ice block, that the man of the house had dumped out in the front yard, was still there, which of course, was as expected, since the temperature here today, is only 17 degrees Fahrenheit. Just in case you're wondering, the block of ice is the result of having an automatic ice maker in a frost free freezer. The girls decided to try sprinkling table salt, rock salt, and sugar on the block to see what would happen (and no, those are not the shoes they wore to church).

The rock, and table salt started to melt the ice almost on contact, but the sugar didn't seem to have any effect.

We moved inside with a printout from the NEED Project, and continued our experiment, in a slightly more scientific fashion.

We set up glasses with one ice cube in each. We left one alone, added one teaspoon of ice to one, two teaspoons to another, three teaspoons to the another, and then also set up one with table salt, and one glass with sugar. Then, we timed how long it took for the ice to melt.

While we waited, the girls amused themselves by looking through our magnifier at the salt, and sugar crystals.

As we expected, the ice with the table salt, and the ice with the rock salt melted at the same rate. The more salt, the faster the ice melted. The ice alone, and the ice with the sugar melted at the same, slower rate.

Finally, we read about what was happening on a molecular level, here, and then performed one final experiment.

We boiled two pots of water, at the same heat, and with the same amount of water, but with salt added to one.

The pot with salt boiled first, and at a lower temperature than the pot with plain water (which went along nicely with our Science Sunday experiment from two weeks ago).

For more kid science ideas, and experiments, check out this weeks Science Sunday link up at Adventures in Mommydom.

It's great to be a homeschooler.


Butterfly said...

Amazing the level of learning just a bit of curiosity can spark! Cool write-up too.

Anonymous said...

is clara wearing britts coat from many moons ago?

An Almost Unschooling Mom said...

Yes, I believe she is, but I thought it was Maddi's coat.

Ticia said...

They are so cute in their coats and church clothes in that first picture.
My kids noticed the salt people had randomly scattered here for the theoretical ice that never showed up.
I love how methodical your teaching your girls to be with these experiments.

Natalie PlanetSmarty said...

This is a very interesting experiment. I think I am going to do a lot of ice experiments when we get to "Ice Worlds" in our geography track.