Halloween Science: Baking Soda & Vinegar Exploration

Give a classic science activity a Halloween theme with one simple addition. Kids will love this Halloween science exploration with baking soda and vinegar. I get commissions for purchases made through the affiliate links in this post.

Halloween Science: Baking Soda & Vinegar Exploration

Combining baking soda and vinegar is a classic science activity that every kids should experience. It’s an introduction to chemistry and chemical reactions. Kids get to practice making predictions and observations as well.

It’s super easy to add in a Halloween theme by using cookie cutters.

Supplies Needed:

• large tray, baking dish, or other container for conducting the exploration
• bowl or small container for holding the vinegar
• baking soda
• vinegar
• Halloween themed cookie cutters (silicone molds or Halloween shaped bowls would work, too)
• orange (or red and yellow) washable liquid watercolors or food coloring (food coloring can stain)
• pipette, dropper, or spoon
• table cloth/towel to protect your work surface (or play outside)
• water (optional)

Protect your work surface by placing a towel under your tray or container. Sometimes the play can be messy or spills might happen. We took our play outside to the patio.

Place the Halloween themed cookie cutters in the bottom of your tray (or other large container). Our trays are from IKEA. They have a large surface area and just enough of a lip to contain some amount of liquid. A large baking dish works also well.

Fill the cookie cutters with baking soda.

Fill a small container with vinegar. Use washable liquid watercolors or food coloring to color the vinegar orange.

If you want your activity to last a bit longer, you can dilute the vinegar with water. This causes less of a reaction (because there is less vinegar to combine with the baking soda), so there will be less fizz. I recommend only diluting by half (half vinegar and half water). You could also do 3/4 vinegar and 1/4 water.

Set up the vinegar next to or on the tray.

Invite your child to drop or spoon the colored vinegar onto the baking soda.

Using pipettes or droppers works on fine motor skills. The small pipettes are difficult for little hands to squeeze, so I recommend starting with droppers that have a larger bulb. I like the droppers from Learning Resources. They are in several of their science kits. We have the Primary Science Deluxe Lab Set. You can also get them in a set of 6 eyedroppers. The twisty droppers are also pretty cool.  

Talk about what is happening to the baking soda and vinegar. What do you see? Look for the bubbles as you add the vinegar. Listen to the sound of the fizz.

Bonus idea: Instead of placing the watercolors or food coloring in the vinegar, you could place drops of color under the baking soda. When your child adds drops of vinegar to the baking soda, they will get a color surprise in addition to the fizz.

The Science Behind It

Baking soda (sodium bicarbonate) is a base and vinegar (acetic acid) is an acid. When combined, they react to form water, a salt (sodium acetate), and carbon dioxide gas. The bubbles produced by the reaction are the carbon dioxide gas escaping the water.

More Halloween Science Activities for Kids

Fizzy Potions Juice Lab – Make color changing, fizzy potions with fruit juice.

Fizzy Spider Web Art – Combine science with art to make colorful and fizzy spider webs.

What’s in the Witch’s Kitchen? Potion Making – Gather up edible ingredients like wiggly worms, slimy frog spawn, and bats with fleas to create your own sensory science exploration and witch potions.

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