Way back in the day, 7Up had lithium in it. So, the chemistry department at the University of Nottingham decided to have a little fun and see if they could put the lithium back into the 7Up. Turns out they proved, rather dramatically, that you can’t, on a Mentos-and-Diet-Coke scale.
The team behind this video isn’t entire sure what happened, because they don’t know how lithium reacts with the other ingredients of 7Up. What was supposed to happen was that the water would create lithium hydroxide and hydrogen gas. Instead, it started boiling and changing color, and by the time the reaction was done, they had a black highly alkaline sludge they couldn’t identify. Because 7Up is clear and lithium salts have no color, the color change in particular took them aback. It’s likely something to do with the sugar in the soda, as that has chemical energy, but they’re still fiddling around with it to learn about the reaction.
Don’t worry, 7Up isn’t killing you. This is pure, elemental lithium being dropped into the soda, and you don’t have nearly enough of that to cause a reaction in your body. In fact, being exposed to lithium is pretty dangerous in its own right. This is just a neat demonstration of the unexpected side of chemistry, and a reminder that the things we take for granted in the world hide secrets for us to unlock.