background image
Make Drinking Water Out of Salt Water!
In many parts of the Earth today, fresh water is scarcer than ever and people,
land, and animals are becoming parched. Scientists are busy exploring ways to
take the salt out of salt water in large quantities. You can help!
What you need:
1
1
/
2
tablespoons of regular table salt
3 cups of water
Plastic wrap
Mixing bowl
Cup or small bowl
Small rock
What you do:
1. Mix the salt into the water
in the mixing bowl and stir
thoroughly until it is dissolved.
2. Place the cup or bowl into
the center of the larger bowl.
Don't let any of the salty water
into it.
3. Cover the bowl with plastic
wrap and seal the edges tightly.
Take a small rock (not too big
or it will break the plastic!)
and place it right on top of the
center of the plastic wrap. All
of the plastic will slant slightly
toward the middle where the
cup is.
4. Put the whole setup in full sun and wait. Within an hour, you should see
water droplets begin to form on the underside of the plastic. They'll flow
and drip into the center of the bowl, and into the cup.
5. Wait several hours, and then take the plastic off. Water should now be in
the small cup.
6. Taste it!! Guess what? No salt! The water vaporized in the heat of the sun,
and then returned to its liquid state. Salt doesn't do that--it stayed behind.
Presto! You really can take the salt out of salt water!
Adapted from:
Make Drinking Water Out of Salt Water, by Julie Williams
http://www.education.com/activity/article/Take_salt_out_of_salt_water/
92