Ingredients:
2+ cups all-purpose flour
1/2 cup salt
1 cup hot tap water
"In large bowl, mix flour and salt. Slowly mix in water while stirring.
When stirring gets difficult, use your hand to knead in the bowl. When you get all the flour off the sides of the bowl
and have one neat doughball, dump it out and continue kneading until desired consistency."
From here we added some additional flour to keep the dough from sticking to our
hands too badly, but not enough to make the dough stiff. NOTE: Our volcano required 3 batches of dough, so make sure
you have plenty of salt and flour on hand!
MAKING THE VOLCANO
Supplies needed:
Flat piece of cardboard
Cardboard tube (from toilet paper or paper towels roll)
8 inch piece of plastic wrap (optional)
Tape
Paint (optional)
1. Tape the cardboard tube to the center of the piece of cardboard. This
will be the center of your volcano, where the lava will come up.
2. (Optional) You can then take the piece of plastic wrap, and with your index
finger at it's center push it down into the tube until you have just the edges hanging out over the sides. This creates
a pouch down inside the tube to put your chemicals in for the eruption, and can be pulled inside-out to clean and then perform
further experiments/eruptions. Tape the edge of the plastic wrap down around the outer edge of the top of the cardboard
roll. I happened to have red clingwrap, and it made for a cool looking volcano!
3. Start piling the dough all around until you have a nice volcano shape.
(For us this required 3 batches of dough). Let dry for a few days.
4. Paint, if desired. For added "realism" we sprinkled sand all over the
volcano while the paint was still wet. Let dry.
ERUPTION DAY!
We performed two different experiments for our eruptions, so that we could compare
the reactions. I recommend doing this OUTSIDE on something that you won't mind staining temporarily (we still have a
red area in our lawn three weeks later).
Experiment #1: Yeast and Peroxide
Ingredients-
Packet of rapid rise yeast
equal amount of hydrogen peroxide
Something to stir with (like a plastic knife, or straw)
Optional: something to color your lava red (we used strawberry jello mix powder,
but use your imagination - food coloring? paint? ketchup? have fun!)
First, sprinkle dry ingredients into "lava tube". Then, pour in peroxide
and stir (being careful not to puncture the plastic liner)! Additional peroxide can be added after the initial "eruption"
to continue the reaction.
I'm no chemist, so I figure we'll re-explore this reaction in another ten years
to see if we can make sense of what exactly went on! :)
Experiment #2: Baking soda and vinegar
Ingredients -
Baking soda and vinegar
(and the optional red coloring of your choice, as mentioned above)
I'd say to just guess-timate your amounts. It's probably about 1 part baking
soda to 3 parts vinegar, but we weren't exact about this at all. As with experiment #1, add your dry ingredients first, then
your liquid, then stir and watch!
An aside: after making our volcano erupt umpteen
times, eventually the plastic liner was accidentally punctured. This actually led to a great demonstration of the gas
being created by the soda/vinegar experiment because the gas flowed down below the liner, inside the tube, and then inflated
the plastic wrap up out of the tube!
