The Chemist Prankster - Time Bombs In Your Soda

Today we got to see some snow in Uppsala! The scenery was even more picturesque. Strolling around, wrapped safely in our heavy coats and gazing at the buildings with the white snow sprinkled roofs, the bare branches on the trees and the cobblestone streets...I've got a great photo compilation for you when I come back ;)

For this post I got you an old time classic (and favorite) exploding recipe: diet coke and mentos! Only today we aren't doing it the traditional way (add mentos in a bottle of coke and wait for the "geyser" to pop), we are looking for a smaller scale explosion to scare the shit out of an unsuspicious victim trying to enjoy their beverage.

(Image source:commons.wikimedia.org)

Ingredients 

• diet soda
• mentos
• water
• ice cube tray

Steps

• Fill the ice cube tray up to the middle and freeze.
• Smash the mentos and add them above the ice cubes.
• Fill the tray with water and put to freezer again.
• When the ice cubes are ready serve your victim some refreshing, cold diet coke and just wait...
• And wait...
• And wait...
• It seems like the prank is on YOU! This joke doesn't work for a very good reason, read on to find out...

The science behind the diet Coke and Mentos explosion:

Although there is not a 100% safe conclusion, the most supported idea is that:
In carbonated refreshments there is a great concentration of liquid carbon dioxide (CO2) under pressure (the higher the pressure, the more soluble CO2 is). When we remove the cap, pressure lowers and CO2 starts turning from liquid to gas (CO2 aq -> CO2 g). This transition is normally slow and happens around the walls of the container. But if we dip other objects in the refreshment we can speed up the nucleation process (the formation of gas bubbles) depending on the objects' texture. 

What is special about mentos?
It's their texture. If you put a mentos candy under a magnifying glass, you'll see that it's not as smooth as you think, but it's rather spongey, full of tiny hollows. These hollows provide the perfect nucleation factor, the perfect bubble popping mechanism. And since those bubbles form very quickly and travel all the way from the bottom, they are released massively and lead to an axploding foamy fountain that is always fun to watch, and a great opportunity for science teachers to have a...blast with their students ;)

Why diet Coke?
Because the aspartame has been proven to lower the surface tension in the water, speeding up the process. There are a few more additives that can work the same way as aspartame (some sugars, citric acid, and natural flavors). And despite what most of us would expect, that the caffeine in the coke would work as a catalyst, this does not seem to be the case.

Why doesn't work the same in the ice cubes?

Because when we smash the candies, we ruin their special texture rendering them useless as nucleation catalysts.

Here you can watch Mythbusters dealing with the mentos 'n' coke explosion:

Watch that they use two kinds of mentos candies, the regular and a flavored one, will it work the same with both?

References

kidspot.com.au-Mentos_in_coke_experiment
wikipedia.org-Diet_coke_and_mentos_eruption
newscientist.com-Science_of_mentos_in_diet_coke_explained

Thank you for stopping by and giving this post a read. I hope you enjoyed it! If you please, feel free to pay a visit to my blog and check out my short stories along with plenty of educational posts and of course my bizarre natural phenomena series. 

Special thanks and mentions go to:

Until my next post,
Steem on and keep smiling, people!