And discussed what ingredients of the Diet Coke and Mentos would lead to the explosion (the acid materials were their guesses) and finally we discussed how this is actually a physical not a chemical reaction (which apparently has been debated a lot…who knew?).
And then I told everybody to get way back and put on their safety goggles….and then there was nothing. So we tried again. And again. Tiny fizzes. But not the explosion of soda I was waiting for. Feeling a bit defeated we discussed why it may not have worked (flat soda and not using a small enough funnel opening were our two guesses), and moved on to our second experiment.
This one, thankfully, worked perfectly:
This is such a fun and simple activity to do with kids. All you need is a balloon, baking soda, and vinegar. I had each boy put a scoop of baking soda in the balloon (if you watch the Bill Nye episode, he tells you the amounts!), and I had poured vinegar into the water bottle. You carefully attach the balloon over the mouth of the bottle, and tada! It fills the balloon.
What we learned:
In order for something to be a chemical reactions the properties have to change when combined (the Diet Coke and Mentos is the coke’s reaction to extra sugary items in the container, thereby trying to force out CO2, but when you are finished, the soda is still soda, and the Mentos are still Mentos).
And after doing some research, we headed back outside with a fresh bottle of Coke, Mentos, safety goggles (Safety First!), and tried again: