4B70.25 - Diet Coke and Mentos (Indoors)
To demonstrate how nucleation sites on the Mentos serve as a catalyst for the release of CO2 from the Diet Coke with the presents of potassium benzoate, aspartame, gelatin, and gum arabic causing a rapid formation of foam.
Place the nerf football in the top of the clear pvc tube that is hung from the hoist. Connect the second part of the tube and raise it up so that it just covers the Diet Coke bottle when it is placed in the stabilizing cone. Load 5-7 mentos into the mentos release mechanism. Place the caution cone and diet coke in the large aluminum pan. Screw off the top of the soda and screw on the mentos release mechanism. When ready, tell the professor to pull out the stopper and stand back.
With the release mechanism screwed onto the Diet Coke bottle and placed under the clear pvc tube, give a count down, pull out the pin and stand back. Observe the foam geyser that is produced by the reaction between the potassium benzoate, aspartame, and CO2 of the Diet Coke with the gelatin, gum arabic, and amount of nucleation sites that are present in the mint Mentos candies.
Resource: "Soda Pop Fizz-ics" by Tonya Coffey, The Physics Teacher, Vol. 46, No. 8, pp. 473–476, November 2008Resource: Myth Busters