Be a Kitchen Chemist. Build a Baking Soda Volcano!
This volcano is made with salt dough, but a paper mache volcano works great too!
The first step for this baking soda and vinegar volcano is to make a batch of Salt Dough. This recipe yields plenty for a volcano. -- Want a smaller batch just to play with? Click this link for a salt dough recipe that makes less dough.
Here's what you'll need to make a volcano:
6 Cups Flour
2 Cups Salt
4 Tbs Oil
2 Cups Water
In a large deep bowl mix all the dry ingredients together. Add 1/2 the water and 1/2 the oil and begin kneading the dough. Mix in the additional water and oil gradually working it in until the dough is smooth and firm. Add more water to the mixture if you feel it's too dry.
After your salt dough is done you're ready to build your volcano. For that you'll need:
Plastic soda bottle (2 liter is good, but a smaller bottle is fine, it just makes a smaller volcano)
Vinegar
Warm water
Red food coloring
6 Drops Liquid dish soap
2 Tbs Baking soda
Cookie sheet
Funnel
Now....Here's HOW to Make a Volcano
TIP: Do a test run of lava flow before building the volcano. It will be much easier to test and pour the liquid out of the bottle before you've covered it in dough. Tweak your ingredients until your get the flow you want.
Stand the clean, dry soda bottle on the middle of the cookie sheet. Press and shape the salt dough around the bottle to look like a mountain/volcano. Screw the top back on the bottle, or at least cover the opening to make sure you don't drop any dough into the bottle. It will mess up the chemical reaction of the eruption.
If your goal is actually making a volcano model you can stop at this point and let the volcano dry for a couple of days, then paint it.
Once your baking soda volcano is ready:
Put a few drops of red food coloring in the bottle then pour in the warm water (tap water is fine) to almost fill the bottle.
Pour liquid dish soap into the bottle.
Add the baking soda to the soapy water mix in the bottle.
When you're ready for the lava to flow, slowly pour some vinegar into the bottle.
Once the baking soda and vinegar mix together you produce Carbon Dioxide gas, which will bubble up and force the "lava" up and out of the volcano. COOL!!
This video will show you how the baking soda solution works.
This volcano is made using paper only. Nice.
The salt dough could also be used with this method to add terrain and texture to your volcano.
TIP: Do a test run of lava flow before building the volcano. It will be much easier to test and pour the liquid out of the bottle before you've covered it in dough. Tweak your ingredients until your get the flow you want. 
