Halloween Frankenbombs

My youngest scientist is turning 1 and we are planning a Halloween party for her complete with a little spooky science. This is one of the simple experiments we are going to do with the kids.

I have always loved the exploding pumpkin bag found here but decided to substitute baking soda and vinegar with 2 good ol’ Alka-Seltzer tablets. It had the same effect but so much easier to execute!

Here’s what you need: Ziploc bag, water, food coloring, and Alka-Seltzer tablets

Here’s what you do:

• Make a Frankenstein face on the Ziploc Bag
• Fill the bag about 1/4 full of water and add food coloring
• Hold Alka Seltzer tablets in the top empty corner of the bag
• Seal bag without dropping tablets in
• Then let go of the Alka Seltzer and shake the bag allowing the Alka Seltzer and water to mix

Here’s our Fraken-bomb in action. How fun is that!?

What’s the science?

Alka-Seltzer is made of sodium bicarbonate (baking soda) and citric acid.  When you toss it into water the tablet dissolves and mixes the acid and base together and releases carbon dioxide.  This is a similar reaction to  mixing baking soda and vinegar. The bag blows up because the carbon dioxide is trapped inside.

Truth be told this bag never burst until the kids kicked it around a bit but there was a lot of screaming and running away in anticipation. The next Frankenbomb we did burst and spewed at the bag opening. Honestly, I considered it a win when Allie told me that it was filling up with carbon dioxide.

We hope you have a Happy Halloween that involves some spooky science!