It’s fall and with fall comes Halloween and Pumpkins. Some years we grow our own pumpkins, other years I buy my pumpkins, but no matter how they arrive, it is always exciting when we get the first pumpkins of fall! This year we kicked off pumpkin season with a Fruit Battery project, then we jumped into a very exciting Halloween Pumpkin Volcano Science Project! Kids love this erupting chemistry experiment.
This year we are putting our pumpkins to good use! It’s early, so we knew that any pumpkins we grabbed now would not make it to Halloween night. Especially since it is below freezing here and snowy. So we nicknamed these first two pumpkins “Science Pumpkins”! That means we are doing as many fun and interesting science activities as we can think of with these pumpkins with no worries about making them last for Halloween.
Our first project was building a Harvest Fruit Battery using Pumpkins and Squash. It was a huge success, which actually surprised me. I was worried it wouldn’t work. But it did. And the kids had a blast with this Pumpkin STEM project. We even powered an LED with our fruit battery! So cool.
After our fruit battery stem project, it was time for a new pumpkin project.
First up I let my kids carve them. I was honestly very surprised how well they did carving the pumpkins. As I tried to calmly let them use sharp knives, they may be tweens, but I still worry! But they were careful and total pros.
Then the big shocker. My sensory kiddos that needed gloves last year, both dove in with bare hands to pull all the pumpkin guts and seeds out! I was amazed! For those of you in the trenches, it takes time, so much time and patience, but it does pay off. Sometimes you don’t even realize how far they have come until moments like these.
After that we washed the seeds and roasted them. Homemade roasted pumpkin seeds are the best!
So now we had carved pumpkins we needed another fun project.
It’s been really cold here and snowy, but the sun came out for a day and melted the snow. Since we could get outside, I decided to do a very messy pumpkin volcano.
And this is really, really messy. I don’t know if I own a bowl or dish that would have been big enough to contain our eruption. So do this outside. Seriously.
CHECK OUT THE VIDEO OF OUR PUMPKIN VOLCANO IN ACTION
PUMPKIN VOLCANO SUPPLIES
For this experiment you will need:
One carved pumpkin
An outdoor space you don’t mind getting a little messy
MAKE YOUR HALLOWEEN PUMPKIN ERUPT!
Take your pumpkin outside and set it on a surface that is easy to hose off. We used an upturned bucket.
Take the top off your pumpkin. Now add baking soda (about 1/2 cup should be right, but adjust as necessary for best eruption). Be careful it doesn’t poof right out the mouth!
In a container mix vinegar with some orange food colouring (or whatever colour you want). We used about 2 cups of vinegar.
Now slowly pour the vinegar into the pumpkin.
Watch as your eruption starts and your pumpkin volcano looks like it is vomiting.
If your kids are anything like mine this will lead to squeals of delight!
THE SCIENCE BEHIND THIS PUMPKIN VOLCANO SCIENCE PROJECT
Unlike our Lemon Volcanoes, we need to add an acid to our base (baking soda), in order to create a reaction. Lemons are naturally very acidic, so for that experiment you do not need anything other than lemons and baking soda. Pumpkins need help. So we add our acid (vinegar) in order to create the chemical reaction that results in our pumpkin eruption.
The chemical reaction taking place is:
CH3COOH (l) + NaHCO3 (s) = CH3COONa (l) + CO2 (g) + H2O (l)
Vinegar or Acetic Acid has the chemical formula CH3COOH. Baking soda is a base also known as Sodium Bicarbonate and has the chemical formula NaHCO3. During this reaction the products are sodium acetate (NaC2H3O2). Sodium acetate is made of 1 sodium ion, 2 carbon atoms, 3 hydrogen atoms, and 2 oxygen atoms. The other products are water (H2O) and carbon dioxide (CO2). Carbon dioxide is the gas that causes the bubbling during the reaction.
Pumpkin + Baking Soda + Vinegar = Puking Pumpkin!
This activity was a ton of fun and the kids ran to grab more vinegar to keep our pumpkin volcano erupting over and over again. Give it a try next time you want to do one last thing with your pumpkin before it goes for composting!