Halloween Chemistry Demonstrations

Try a Halloween chemistry demo. Make a pumpkin carve itself, turn water into blood, or perform an oscillating clock reaction that switches between the Halloween colors of orange and black.

01
of 09

Make Spooky Fog

Making dry ice fog is a classic Halloween chemistry demonstration.
GUSTOIMAGES, Getty Images

Make smoke or fog using dry ice, nitrogen, water fog or a glycol. Any of these Halloween chem demos can be used to teach important chemistry concepts relating to phase changes and vapor.

02
of 09

Water into Blood

Use a pH indicator to turn water into blood for Halloween.
Tetra Images, Getty Images

This Halloween color change demonstration is based on an acid-base reaction. This is a good opportunity to discuss how pH indicators work and to identify chemicals that can be used to elicit color changes.

03
of 09

Old Nassau Reaction or Halloween Reaction

Orange Liquid in a Flask - Old Nassau Reaction or Halloween Reaction
Siri Stafford, Getty Images

The Old Nassau or Halloween reaction is a clock reaction in which the color of a chemical solution changes from orange to black. You can discuss how an oscillating clock is made and what conditions might affect the rate of oscillation.

04
of 09

Dry Ice Crystal Ball

This is a dry ice bubble.
Anne Helmenstine

This is a dry ice Halloween demonstration in which you make a sort of crystal ball using a bubble solution filled with dry ice. What is neat about this demonstration is that the bubble will achieve a steady-state condition, so you can explain why the bubble reaches size and maintains it rather than popping.

05
of 09

Self-Carving Exploding Pumpkin

Igniting acetylene gas produced by a chemical reaction blows the face out of a pumpkin.
Allen Wallace, Getty Images

Use a historically important chemical reaction to produce acetylene gas. Ignite the gas in a prepared pumpkin to cause the jack-o-lantern to carve itself!

06
of 09

Make Frankenworms

Use science to turn ordinary gummy worms into Frankenworms.
Lauri Patterson, Getty Images

Turn boring lifeless gummy worms into creepy zombie Frankenworms using a simple chemical reaction.

07
of 09

Bleeding Knife Trick

Make a blade appear to bleed using a trick of chemistry. No actual blood is necessary!
Jonathan Kitchen, Getty Images

Here's a chemical reaction that appears to make blood (but really it's a colored iron complex). You treat a knife blade and another object (such as your skin) so that when the two chemicals come into contact "blood" will be produced.

08
of 09

Green Fire

This jack-o-lantern is lit from within by green fire.
Anne Helmenstine

There's something eerie about the green fire that just screams "Halloween." Explain how flame tests work then illustrate how metal salts can affect a fire by using a boron compound to produce green flames. Perform the reaction inside a jack-o-lantern for added effect.

09
of 09

Goldenrod "Bleeding" Paper

Goldenrod paper is a special paper containing dyes that react to pH change.
Paul Taylor, Getty Images

The dye used to make goldenrod paper is a pH indicator that changes to red or magenta when exposed to a base. If the base is a liquid, it looks as though the paper is bleeding! Goldenrod paper is great anytime you need inexpensive pH paper and perfect for Halloween experiments.