Temperature of Diet Coke vs. Time of Geyser By: Mark, Brianne, Tanya, Will, Mara

1. Experimental Design Setup 3 – 2 liter bottle of Diet Coke 18 Mentos 3 paperclips 3 Strands of Thread Drill Stopwatch Cold: The bottle was placed in the refrigerator until it became 42° F Room Temperature: The bottle was left in a room of average temperature until ready to perform experiment which was 78° F Warm: The bottle was poured into a bowl, heated for five minutes in the microwave, then poured back into original bottle now measuring 120° F Background Information When Mentos and Diet Coke mix together, it creates a tall geyser. The Diet Coke creates holes on the outer surface of the mentos called nucleation sites. We wanted to find out if the temperature affects the geyser. The gum arabic breaks the surface tension of the soda, allowing the carbon dioxide bubbles to escape rapidly, which creates the geyser. Temperature of Diet Coke vs. Time of GeyserBy: Mark, Brianne, Tanya, Will, Mara Hypothesis We think that the warmer soda will have a shorter period of time that the geyser goes off than the soda kept at room temperature and the cold soda. The warm soda's geyser will last for a shorter time than the others because the heat will cause the soda to lose carbonation and go flat. • Method • Drilled 1/8th inch holes in the bottle caps and the 18 mentos • Tied a paperclip to the bottom of a strand of thread 7 inches long • Threaded 6 mentos onto each strand of thread (three total strands) • Bottle of correct temperature placed on a board in the yard • Thread cartridge through hole in bottle cap • Screw the cap onto the bottle while holding cartridge • Release cartridge while partner starts the timer • Record data • We are testing the temperature to see if it affects the • time the explosion lasts. The temperature is being measured in degrees Fahrenheit and the time is being measured in seconds. Variables Independent variable: The temperature of the diet coke Dependant variable: The time that the geyser Lasts Constants: Amount of diet coke, size of container, number of mentos, size of hole Abstract The main goal of this experiment is to determine whether the temperature of the diet coke affects how long the geyser lasts. We are testing three diet coke bottles at cold, room temperature, and warm and recorded the length of the geyser effect that results from the reaction. We found that the colder bottle had more of a reaction with the mentos than the room temperature bottle. We also found that the warm bottle had no reaction Conclusion The purpose of the experiment was to find out if the temperature of the Diet Coke affects how long the geyser lasts. We hypothesized that the temperature of the Diet Coke does affect how long the geyser lasts and our experiment proved that it does. A possible error we made was not measuring the coke we poured out of the bottles. The amount of diet coke left in the bottles could have effected how long each of the geysers lasted. A way to improve this experiment in the future would be to make sure that all of the bottles have the same amount of coke in them after pouring out the extra to make room for the Mentos. So if you want to save money and keep your sodas from going flat (lack carbonation) keep them in the refrigerator.