Kids will have an explosive soaring good time with this science activity of making Water Rockets! I'll be demonstrating two different kind.
Water Rocket 1:
You will need: plastic 2-L pop bottle, water, 1 cup vinegar, 2 tablespoons baking soda, paper towel, cork (and tape), screw and board (for launch pad)
Now try this:
1. Fill a 2-L pop bottle 1/3 full with water (you may add food coloring for fun colors).
2. Add the 1 cup of vinegar to the 2-L pop bottle.
3. Place the 2 tablespoons of baking soda on the paper towel and roll up the paper towel so that it can easily fit into the 2-L pop bottle.
4. Place a screw securely into a board for making the launch pad. The screw should be sticking up out of the board.
5. Screw the cork into the screw on the launch pad.
6. When ready you will need to move quickly on this last step: insert the baking soda into the 2-L pop bottle and insert the cork that is screwed to the launch pad. Invert so launch pad is flat and stand well back for some explosive fun!
Water Rocket 2:
You will need: plastic 2-L pop bottle, water, large PVC pipe cut 6 inches in length, tape, air pump (used for a bike)
Now try this:
1. Fill the 2-L bottle ½ full with water (you may add food coloring for fun colors).
2. Wrap tape around the nozzle on the air pump as to make it fit snug into the top of the 2-L bottle.
3. Place the 2-L bottle onto the large PVC pipe (this is your launch pad).
4. Place the taped nozzle onto the top of the 2-L bottle and invert.
5. Begin pumping air into the bottle with the air pump. Once a good amount of pressure has been built up be ready for an explosive good time!
Explanation:
For Bottle Rocket 1: When you combine baking soda (sodium bicarbonate) with vinegar (acetic acid) a chemical reaction takes place. This is evident by the bubbling that you see. This bubbling is a gas that is released called carbon dioxide. Attempting to trap this gas inside a container results in a build up of pressure. After enough pressure builds up the bottle pops off of the cork (launch pad) and soars into the air because air always goes from a condition of high pressure to low pressure.
For Bottle Rocket 2:
Pumping air into the 2-L bottle causes a lot of air forced inside a relatively confined space. This air is being compressed as it is forced in this confined space and so it is at high pressure. As the pressure becomes high enough it's only way to expand is to so at the bottle's weakest point and that is where the nozzle is fitted into the bottle. The bottle soars as air moves from a condition of high pressure to low pressure.
For more ideas: www.chemicalkim.com