Solar Distiller

Grade Levels:
7-9

Questions:
Can you distill clean water from muddy water?
Can you distill clean water from salty water?

Possible Hypotheses:
You can/cannot make clean water from muddy water.
You can/cannot make clean water from salty water.

Materials:
Two large plastic containers
Clear plastic wrap
Masking tape
Two small rocks
Two small glasses
Two tablespoons of dirt
Two tablespoons of salt
Water

Procedure:

1. Fill both plastic containers with one inch of water. Mix the dirt into the water in one and the salt into the other.
2. Place one empty glass upright into the middle of each plastic container. Make sure it remains empty.
3. Cover both plastic containers tightly with plastic wrap and seal them with tape. Place a small rock in the middle of the plastic wrap directly over the glass but not touching it.
4. Place the stills in a sunny place for two hours. Examine any water that forms in the glass. Record your observations.

Analysis and Conclusion:
Did the stills make clean water? Can you explain how they worked? Can you imagine a situation in which this knowledge could save your life?