Kids will LOVE this sand volcano science experiment!
Believe it or not, we have never made a baking soda and vinegar volcano! I know, right?! So we decided that we needed to try this classic childhood activity. However, as I started to think through it, I wasn’t sure what to use to build the volcano. Paper mâché is messy and takes a long time to dry. The amount of clay needed to make this would be expensive, and would also take a long time to dry. We found a tub of sand in the garage left over from last year’s VBS and decided to try a SAND VOLCANO!
I highly recommend this fun activity! The kids loved it, and it’s easy to make the volcano erupt over and over.
Supplies Needed for a Sand Volcano Science Experiment:
- Sand and a sandbox – we used an under-the-bed tub
- An empty water bottle
- Baking soda
- Plastic spoon
- Dinosaur toys – optional
- Red food coloring – optional
NOTE: You can see from the photos that we used some food coloring to make our “lava” red. However, I do want to point out that the food coloring will make hands pink when the kids handle the sand again. We probably used too much – 6-7 drops per squeeze bottle of vinegar. I would either try less coloring or just use plain baking soda and vinegar. It will be just as fun without the coloring!
You’ll want to have plenty of baking soda and vinegar on hand. I buy our vinegar in large bottles from Costco, since we also use it for our homemade cleaning solution (gets rid of bathroom stink) and to remove the stains from pans.
Moisten your sand so that it’s moldable, but not too wet.
Then build a mountain around your water bottle. You’ll want the mouth of the bottle to be uncovered at the top.
Sand makes it so easy to build a good mountain! Add some dinosaurs running from the eruption, or add other toys. It’s up to you!
Then put some baking soda in the bottle. We didn’t measure amounts, but I think we used about 1/8 cup. It doesn’t have to be exact! You certainly don’t need to fill the bottle, but if you don’t add enough, the eruption won’t be enough to overflow out of the bottle.
We found that a funnel made it much easier to get the baking soda into the bottle.
I had a squeeze bottle on hand, so we used that for the vinegar. It worked really well! Squeeze in a LOT, and then pull out the bottle quickly.
Then the volcano erupts! Run, dinosaurs!
The science of chemical reactions:
We found that we could add more vinegar and get a second eruption! But it all depends on the amounts used. This is a good science concept to discuss with the kids. The reaction of baking soda with vinegar is a chemical reaction between sodium bicarbonate (baking soda) and acetic acid (vinegar) to form carbon dioxide (the bubbles), water, and sodium acetate.
A certain amount of baking soda will react with a certain amount of vinegar. If you there is unreacted baking soda left in the bottle after the eruption, you can add more vinegar and get it to react again. If there is unreacted vinegar left in the bottle, you can add more baking soda and get a reaction. But if both are “used up,” you’ll need to add more of both to get the volcano to erupt again.
After the eruption, you can rinse out the water bottle and try it again.
Have fun with science!