Chemistry

Elephant Toothpaste

Hello everyone.  I am having a problem with the elephant toothpaste.  I am using yeast, potassium Iodide, and sodium iodide.  These are all working, but i am looking for the wow factor.  I have viewed some videos where the toothpaste shoots up out of the bottle.  Does anyone know what the catalyst is?  The ones i have been using it just oozes out.  

Jesus Sustaita
Jesus Sustaita
10 Activity Points

Are you using 30% hydrogen peroxide from a chemical supply (like Flinn)? A long narrow container, like a graduated cylinder also helps. I use potassium iodide and typically get a nice fountain followed by oozing.

Rebecca Falin
Rebecca Falin
71400 Activity Points

Jesus, I find much less expensive 30% H2O2 at a local store that sells water purification systems. The concentration is key since the reaction is exothermic enough to auto-accelerate. Be sure you test it with small amounts first, because those higher concentrations of H2O2 present additional hazards. Best, Bryan=

BRYAN SMITH
Bryan Smith
310 Activity Points

I have done all that, but on some videos the toothpaste goes flying out about 10 ft. Any more ideas?

Jesus Sustaita
Jesus Sustaita
10 Activity Points

The key to a fast, huge eruption is pressure. If you use a graduated cylinder you do not get as much pressure forcing the material out of the top as you would if you used a large conical flask. Larger reaction area at the base (more gas produced) confined at the neck/mouth of the flask, resulting in greater pressure and a more dramatic eruption. Steve Spangler has some material on a patriotic demo (https://www.stevespanglerscience.com/blog/2011/07/04/patriotic-monster-foam-exploding-hydrogen-peroxide/). If you look at the picture you see that they are using conical flasks. **I get the 30% H2O2 from a pool supply store (Leslie's).

Cris DeWolf
Cris DeWolf
11645 Activity Points

Ok. Thank you. I will try it that way. I have been using a graduated cylinder.

Jesus Sustaita
Jesus Sustaita
10 Activity Points

Jesus, It also might be the age of your 30% hydrogen peroxide. H2O2 will degrade over time so depending on its age, it will not actually be 30%. When did you purchase your hydrogen peroxide?

Ruth Lehmann Hutson
Ruth Hutson
61810 Activity Points

Hello Jesus,

First, I don't think you want 10' spumes coming out of your cylinder!  It's probably a concentration and quantity thing at play to get those.

We always stored our peroxide in the science lab fridge to keep it from decomposing and I've always done this demo with manganese dioxide powder.  Always seemed to work well.  It's fun to do the oxygen test by dropping a glowing wood splint into the cylinder and watching it re-ignite and slowly descend into the suds. 

Regards,

Gabe

Gabe Kraljevic
Gabe Kraljevic
2408 Activity Points

I always buy the peroxide at Sally's Beauty Supply.  Its not called hydrogen peroxide (30/40 volume clear developer), but its the same stuff and you can get 40% there.  Stronger concentrations of KI will help as well.  I've never really gotten the big shooting demo, but the kids like it either way.

Chris Leverington
Chris Leverington
3900 Activity Points

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