You probably saw this kind of video online. A person put Mentos into a bottle full of coke. Then a huge amount of bubble form and push the all coke out of the bottle. It is really fun and could be a good prank on your friend ;). But how does it work?? Is there some chemical reaction happening? Or is it a physical reaction. I thought is a chemical reaction between the mint and the CO2 in the coke. But after some research (like watching video on YouTube for 10 mins xD) I realized I was wrong. It is in fact a physical reaction.
As you probably know there are lots of CO2 (carbon dioxide) in coke. Whenever those molecules touch objects with tiny dents, scratches, and bumps on them, the CO2 will quickly change into CO2 gas (the bubble). This is why you can see a bubble forming on the surface of the bottle. Also when you put a straw into the bottle. Bubbles will form on the straw and push it up. Mentos may look like it has a smooth surface. But if you have a strong microscope, then you can see it has lots of tiny dents, scratches on its surface.
In the picture above the red and black things are the CO2 molecules. When it touches the dents on the Mentos surface bubble will form. The more dents the more bubble. If you want to test this theory out. Buy a bottle of coke and put some object with a not very smooth surface (like sand etc.). You will see the same reaction :D. This is the science be hide Mentos and coke reaction 🙂 I hope you like it.
Science Scholars 2019 