The mentos and coke thing is a reaction between the carbonation and the rough surface of the mentos. The water would dissolve the surface rather quickly, even in ideal scenarios, and as you melt the ice, you wouldn't be able to re-expose the surface fast enough for a meaningful reaction. Just all around an impractical plan.
If I remember right from a video back when mentos and Coke was all the rage, it wasn't just the texture of the mentos but there was also a chemical reaction in the combination of the two is what led to the violent reaction.
Would you be able to find the video? I had never heard of this, and can't imagine what "chemical reaction" could occur beyond the carbon dioxide simply coming out of solution.
Even if it didn't change the texture, it wouldn't be a sudden explosion, but a slow release. The ice would melt off, slowly exposing the surface of the Mentos. To get the explosion they want you have to throw the Mentos in quickly.
What if you had piece of ice with an air cavity where the Mentos is placed, then sealed in? I think that might work, bit it’s certainly tricky to set up.
We freeze the end of a rope in ice that they unknowingly throw in their drink. The other end of the rope holds a bucket of water above the chair they sit in. Once the ice melts, the rope will slip out and the water will come down on them. They will never know what happened!
Put two ends of a cable under that person's chair, once water comes down it will close the circuit, which will in turn cause a piano to fall on their head!
Would that even work? As the ice melts, only a small part of the mentos would be exposed, with a gradually increasing surface area. But I'd expected it only works because of the whole surface being suddenly exposed.
Perhaps dip them first in a simple syrup to buy a little time, then start with very chilled water, add the mentos, then freeze quickly? I have doubts about the whole affair though.
Ice would expose mentos way too slowly. Mentos being in water and freezing would have already removed the texture that makes it work to begin with. By the time the ice melted enough a lot of the carbonation would have already escaped the soda. One mentor isn't enough to cause much reaction. The soda would be cold from the ice and that slows the release of the cO2....
If I served my friends soda, they'd not be friends anymore. This establishment isn't a Chuck E..Cheese and if all I have in the fridge is soda, you're getting iced water or tea/coffee.
Imagine being too lazy to tend to your guests with what they request, and too cheap to lose $0.08 of your 2L coke. "this ain't no fancy shit like the rat house, and get your ass your own tp too. fuck washing your hands on my dime, the fuck is this, sears? 50 cents for 5 seconds. wifi? Cent a megabyte. bed? no. get the fuck out at midnight. that includes you babe!"
You prob the kinda guy who would charge $0.54 a mile for 'business wear and tear' reimbursement even though your Prius costs $0.16 to go the same distance - and you're just driving your friend home. Who lives on your street, and you were headed home anyway. "It costs money to be in my aura of greatness! Seatbelt $25 btw."
If you come into my house, you get water, beer, juice, kombucha, wine, at least five tea options, coffee, or even a scotch if you want.
Cheap would be offering them something that's full of sugar, artificial flavour, costs me fuck all, and usually comes with a Happy Meal. I don't insult my friends like that and they wouldn't do it to me either.
Step up your game. It doesn't cost much to be a good host.