Believe it or not, research scientists have actually concluded that Diet Coke produces the best stream of flying soda (much to the joy of the Mentos Experiment enthusiasts). I received an email from Dr. Joe Maglaty, Director of Education Outreach from the Merck Institute for Science Education with this information:
I recently came across an article that you may, or may not, be aware of. In the April issue of the Journal of Chemical Education, a chemistry professor from Illinois State Univ. took on the analytical process for showing gas solubility in aqueous solution - that is, how much carbon dioxide (CO2) is released from soda (pop) using ultrasonic energy. Since ultrasonic waves provide millions of nucleation sites at the wave nodes inside the soda bottle, this technique is much more effective in releasing CO2 than any physical substance, such as Mentos or Lifesavers. The quantitative results are quite impressive, with the bottom line being that Diet Coke at room temperature is the best way to eject most of the soda into a fountain.
The Journal of Chemical Education article probably gives you more information that you’d ever want on the topic. A PDF of the full text is also at this location. With this phenomena of releasing carbon dioxide quickly from a gas/liquid mixture, more teachers should take advantage of this opportunity to explore this science with their students. Everyone should share in this excitement and be involved with inquiry based, hands-on and minds-on science activities that helps us understand and learn from the world around us.
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June 21st, 2006 at 2:08 pm
I am a Pre-K teacher putting on a Science camp in Texas this week. Let me assure you, clear diet drinks only produce a gurgling stream of about 3-4″. I was so disappointed not to have the 8″ shoot I was expecting. It was a real let down for the kids. I promised them we would try it again in two days with diet COKE this time. I used the clear soda hoping it would not stain their clothes when it sprayed out … my bad for not tryng the experiment ahead of time with the clear soda!
June 25th, 2006 at 8:24 pm
I taught a science camp for 3 & 4 year olds in Houston and we tried pretty much every soda out there over the course of a week…it became a daily ritual. We concluded that diet Coke does indeed soar the higest (one student wanted to know if that’s what makes rockets go…). Diet Sprite came in second, with orange soda performing at the lowest height - only about two feet. We tried funneling the Mentos in, using a test tube, and on string - the test tube worked the best for us.
We had a lot of fun, but the best part was how excited the children were about these activities and how thrilled they were to move on to related activities. I teach at a school where the children come in very prepared academically, but many missing the joy of discovery and a desire to experiment with materials. Thanks for so many wonderful ideas shared here.
June 26th, 2006 at 6:57 am
And it’s true! Our scientific research……outside my parent’s home on Mother’s Day with many friends, family and curious neighbors watching, proved the same thing.
Most were betting on whether we’d be able to drop in the Mentos w/o being completely drenched! And we also found that if you don’t get all the Mentos in, that does affect the quality of the “plume”!
Thanks Steve! Another example of if you get it to the dinner table, you’ve won!
September 14th, 2006 at 9:51 pm
I received an email with this information…
I have some additional information on this experiment. I’m pretty sure the reason that Diet Coke works better than regular is because the diet sodas contain more carbonation than regular sodas. I’ve worked in several fast food places, and the diet beverage syrups are always mixed with a higher carbonated water to syrup ratio than the regular sodas. For example, Coke is mixed at 5:1, and Diet Coke is mixed at 5.2:1
Dustin Oliver
May 28th, 2008 at 9:02 pm
Hi.Ice it really Coke or Deit coke??
May 29th, 2008 at 12:17 am
Hey, Amber! It’s Diet Coke, not regular Coke. the Diet Coke works best because regular cola doesn’t have as much carbonation as the diet colas have. Thanks for asking!