You can’t really do a series on baking soda and vinegar without bringing out the volcanoes. But since most preschoolers have very little practical experience with volcanoes it doesn’t make sense to do any sort of a unit on the things. Instead, we try to get the sense of one in the hopes that this knowledge helps them learn about them later.
First you need a volcano. We had made play dough in class with the kids a few days before that had somehow not kept well, so we used that. The children helped even though they really had no idea what we were going for. We tried showing them volcano pictures and read a few books but the information didn’t transfer well. We made two volcanoes and put them on trays that we took outside. We put a small pile of baking soda inside each model.
Since we’re not going for realism, I let the kids pick the color for the lava. On the day I took these pictures, they first picked green. Unfortunately, since the play dough we made was blue, it wasn’t quite the thrill it could have been. The red lava was much more interesting for the second batch.
As we had practiced with droppers and syringes the day before, that’s what we provided for adding the vinegar to the baking soda. We were able to do this for quite awhile without reloading. I was a bit surprised at how little baking soda I had to add for this experience.
Even though we weren’t studying volcanoes we did talk about lava and magma as well as how hot it all would be if they were real. Some how igneous rocks even got mentioned.
I highly recommend doing this outside or in your sensory table if you can’t go out. It was spring when we did this, so we all had jackets on and it was still fine. We had plenty of towels with us but didn’t really need them. The biggest temptation for them was not to put their hands into the volcanoes. While that makes for a fun ending, the play dough gets very squishy during the eruptions and can’t support a child’s weight. Once the hands get in there, it’s all over. And of course, that’s how it ended!
Allergy Note: We did this with gluten-free play dough. If you have a gluten allergy in your class, by all means do the same. It works fine. If you don’t, regular play dough will work just as well if not better.
Need a refresher on the chemical reaction itself? Baking soda + vinegar = water + carbon dioxide + sodium acetate (more or less).