Experiment 1: Drinking Water from Salt Water

I don't know about where you are, but it's been hotter than Billy Blue Blazes here. (though, now I'm curious about who Billy Blue is and who set him on fire....lol). One of the ways we try to bear the heat is through doing experiments. They can be fun, cheap, easy and educational! Drinking water is becoming more and more scarce the world over as fresh water supplies are evaporated due to global warming and droughts. You can use the following resources to do some research on the current water shortage situation: http://drinkingwaterz.com/2369-shortage-of-drinking-water.html http://whyfiles.org/131fresh_water/2.html

One of the things that has intrigued scientists from the time we emerged from the caves, was how to take the plentiful salt water of the seas and oceans and make them palatable for drinking. Ok, onto the experiment, this is a small scale version of one of the methods scientists are evaluating.

  Supplies:

• 1-2 TBS table salt
• bowl
• 3 cups water (tap water is fine)
•  small bowl or coffee cup
• stone
• thick plastic wrap

Procedure:

1. pour watere into the larger bowl
2. mix salt into the water until it is dissolved
3.  place the small bowl or cup into the water CAREFULLY, you do not want to let any of the water to flow ov the sides of the cup.
4. Place the stone in the center of the plastic wrap, so at the wrap angles down into the cup a bit.
5. carefully place the bowl in the sun
6. wait several hours. You should see water droplets on the inside of the plastic wrap dripping into the cup.
7. after a few hours allow student to taste the water in the cup - it won't be salty!

What happened:
The water from The bowl evaporated, condensing on the underside of the plastic wrap (which is why heavy duty plastic wrap is so important, lesser quality plastic wrap will allow the water vapor to escape and leave the cup empty.) salt doesn't evaporate, so essentially the evaporation process separates the water molecules from the salt ones.

Gulf of Mexico Oil Spill

With the tragic events leading up to the large oil spill in the Gulf of Mexico, I felt it was important to teach my children what is so terrible about the situation.
Oil experiments really get the point across easily to younger children. Pour a cup of oil in a small bowl and add a few drops of food coloring. Then pour colored oil into a big bowl of water. The children can place a few toys (or if you really want to proove a point use a small stuffed animal) in and see how difficult it is to get the oil off. You can also experiment with different means of getting the oil out of the water!

Here are some of the resources I've used:

Big list of resources - Earth Scouts
Oil & Pain Contamination Activity
Effects of Oil Spills on Birds
Oil, Oil Everywhere - a book on the Exxon Valdeze with worksheets and lesson plans
Fossil Fuels, Facing the Issues
Impact of Oil Spills on Our Oceans