MadSci Network: Edible/Inedible Experiments Archive
Baking Soda Volcano
Area of Science: Chemistry Meant for Grade 4-6 (age 8-10).
This experiment is barely edible. An adult should be present. Overview:
Create quite a fizzle by mixing baking soda/sodium bicarbonate - a base with vinegar/acetic acid. Well.. it's theoretically 'edible' but I wouldn't recommend
tasting it (yuck!).
1. Baking Soda - Make certain the box says 'soda,' and not 'powder.' 2. Vinegar
3. A container to hold your reaction.
In 4th grade we made a plaster of Paris volcano with a well in the middle to hold the 'reagents.'
4. Paper towels, depending on the extent of mess you plan to make. Safety:
Though the reagents are harmless, it might be a good idea to take precautions to make sure the stuff bubbling off doesn't get in your eyes. How to do the experiment:
1. In a container place some of the baking soda.
2. Pour in some vinegar
3. Watch what happens.
The above reaction represents an acid base reaction, specifically:
baking soda acetic acid acetate ion
| | |
NaHCO3 + CH3COOH --> CO2 + H2O + Na+(aq) + CH3COO-(aq)
(aq = aqueous, or in solution)
to break it down further: +-NaHCO ? Na(aq) + HCO(aq) 33
+-CHCOOH ? H(aq) + CHCOO(aq) 33
+-H + HCO ? HCO (carbonic acid) 323
HCO ? HO + CO 2322
The acetic acid neutralizes the basic sodium bicarbonate. Note that carbon
dioxide is given off in the process, creating the fizzes, pops and crackles.
Alka Seltzer experiment
• Materials: Alka seltzer, film canister, water & pushpin or similar
• Develop hypothesis and write in science journals
• Put 20 mm water (about 4 tsp.) into canister
• Add ? of the effervescent tablet, cover and observe
• Repeat, adding ? a tab, cover and observe
• Repeat again, but this time, put a few small holes in canister lid. Add ?
a tab, cover with lid and observe.
Write up your experiment: Don’t forget to include your hypothesis,
materials, procedure, results & conclusion
From Volcano Live http://www.volcanolive.com/model.html
; small drink bottle
; 60 ml water
; 1 tablespoon baking soda
; 1/4 cup vinegar
; orange food colouring
; few drops of detergent
; small square of tissue.
Making the eruption
Place the water, soap, food colouring and vinegar in the drink bottle. Wrap the baking soda in the tissue and drop into the bottle. The volcano model will then erupt.
For extra realism
The volcano can be made more realistic by enclosing the structure in home made play dough. Mix 6 cups of flour, 2 cups of salt, 4 tablespoons of cooking oil, and 2 cups of water in a large bowl.
Mix the ingredients by hand until smooth and firm. Build up the mixture around the drink bottle to create the mountain. Lava channels and vegetation can be built around the volcano.