Make a Spooky Color-Changing Bottle

Get into the spooky season with this fun experiment. Shake salt into a green bottle and watch it split into blue and yellow layers.

 

Materials you'll need

• small glass bottles with lids
• acetone (ask a grown-up to handle this)
• blue glitter
• coffee filter
• liquid measuring cup
• water
• yellow food coloring
• salt

⚠️ Warning: Grown-ups only on the acetone. It's flammable and gives off strong fumes, so work in a well-ventilated space away from any flame or heat, and wear gloves and eye protection. Keep lids on the bottles whenever you're not pouring.

Step-by-step tutorial

Step 1: With a grown-up handling the acetone, pour ¼ cup of acetone into a small glass bottle and add 1 tablespoon of blue glitter. Cap it and shake until the liquid turns blue.

Step 2: Pour the blue liquid through a coffee filter into a liquid measuring cup to catch the leftover glitter.

Step 3: Add ¼ cup of water to the second bottle, then add a few drops of yellow food coloring and swirl until it's bright yellow.

Step 4: Slowly pour the blue liquid into the yellow water. Cap the bottle and shake until everything turns green.

Step 5: Pour in 1½ tablespoons of salt, cap the bottle, and shake well to dissolve it.

Step 6: Set the bottle down and watch the green split into a blue layer on top and a yellow layer below. Shake it as hard as you want. The colors will separate every time.

Learn more

This bottle works thanks to the salting-out effect. Water and acetone normally mix together completely, but salt grabs onto water molecules so strongly that the acetone gets pushed out of the mix. Acetone is lighter than salty water, so it floats to the top. The blue color from the glitter sticks with the acetone, and the yellow food coloring sticks with the water, which is why you end up with a blue layer over a yellow one.

Hooked on watching liquids stack into layers? Build a Density Tower with eight kitchen liquids, from honey on the bottom to rubbing alcohol on top.