What Is All The Fuss About Sweets Reacting With Coca Cola And Exploding?

In the US, some people have discovered that putting Mentos sweets into diet coke causes an explosive reaction. There are several videos showing the reaction all over the internet. Some are the original but others have since been done as copycat videos by other people setting up the same experiment.

Chemistry students all over the world seem to be talking about it. This is maybe because chemistry in schools is not longer as exciting as it used to be with nothing that fizzes or explodes or pops being allowed under new safety rules.

So why do the sweets cause the explosion? The explosive reaction seen with the sweets may occur because of the rough and pitted nature of the sweet. The holes and pits act as nucleation sites for release of the gas out of solution. When this happens rapidly, the pressure on a closed bottle increases. So, if you put several sweets into a nearly full bottle of coke and the put the lid back one, lots of gas would come out of solution and explode the bottle. This is dangerous so don't do it!