Halloween STEM Fun!
Have some STEM fun at a Halloween party or in class this October with a Witch’s Brew STEM Activity! Halloween can be such a fun time for kids. Why not infuse some learning into your Halloween with this activity?
Many of the STEM challenges I’ve developed over the years are heavy on the E (engineering), but this one is heavy on the S (science)! This is a great way to introduce chemical reactions to kids. Combining baking soda and vinegar are a favorite way to show a chemical reaction. In this activity they will be labeled as spooky ingredients for a fun Halloween STEM twist!
Halloween STEM – Getting Started
You will need baking soda, vinegar, and food dye, but aside from that use what baking ingredients you have on hand (avoid flour and other common allergens). You can use dish detergent, salt, sugar, cornstarch, water, oil, corn syrup, spices, sand, etc. Add the food dye to the vinegar so that the students will be drawn to use at least one of the correct ingredients. If you want to make it more challenging for older students, add the dye to every liquid. Have your students work in small groups to minimize the amount of ingredients they’ll use, and use small containers so they aren’t attempted to make large quantities of the potion.
I used garlic powder for vampire toenails so that ingredient would be really smelly! You will also need mixing bowls and measurement tools, such as small scoops, teaspoons, or medicine droppers or cups. Your students will try to come up with a recipe with the fewest number of ingredients. That means there will be a lot of dumping out and starting over again. If you can do this in a kitchen, it will be easier to clean up! Another fun alternative is to take it outside (weather permitting). The vinegar smell can get overwhelming after awhile, so if you are doing this activity inside please make sure your room is adequately ventilated.
Record Your Data
Record the ingredients used and whether or not the potion bubbled. Once there is a working potion, they will attempt to reduce the number of ingredients. They can eliminate the ingredients one by one or possibly more than that at a time. The fun part, of course, is mixing up the witch’s brew! When the kids have narrowed the ingredients down to 5 or fewer, they should share the recipe with another group to verify that it is repeatable.
Download the Halloween STEM Printables
You can download more details about this activity and the printable pages at Teachers pay Teachers:
After the activity is over, use a large jig of vinegar and baking soda to reveal to the students what the ingredients actually were, and discuss what is going on here. While talking about what is going on, it may help you to use this great video from Crash Course Kids about chemical changes: