Carbon Sugar Snake

Materials: ★★★ Requires materials not commonly found in school laboratories
Difficulty: ★★☆ Can be done by science teachers
Safety: ★★★ Only to be attempted with adequate safety procedures and trained staff

Categories: Chemical Reactions, Combustion, Compounds, Kitchen Chemistry

Alternative titles: Sugar and Baking Soda Snake

Summary

A mixture of sugar and baking soda is ignited with lighter fluid on a sand base, producing an expanding black "snake" of carbon and sodium carbonate as gases from decomposition push the solid upward.

Procedure

Mix 4 teaspoons of powdered sugar with 1 teaspoon of baking soda in a small bowl.
Fill a pie tin with sand and form a small mound in the center with a shallow depression at the top.
Carefully soak the sand mound and depression with lighter fluid or ethanol.
Place the sugar–baking soda mixture into the depression at the top of the mound.
Using a lighter or long match, ignite the sand near the mixture and observe as the black snake gradually rises from the burning mound.
Allow the reaction to finish and cool completely before disposal.

Links

How to Make a Carbon Sugar Snake at Home - Saint Louis Science Center:

📄 Carbon Sugar Snake - KiwiCo: https://www.kiwico.com/diy/stem/crazy-chemistry/carbon-sugar-snake?srsltid=AfmBOoocR3hH00MADz9l7ZabVqHFKUpT2QryFdLhNP1GoGWb0t4kkhNC

Variations

Replace powdered sugar with granulated sugar to compare reaction speed and structure.
Use ethanol instead of lighter fluid for a cleaner ignition source.

Safety Precautions

Adult supervision required; only older students should attempt this demonstration.
Perform outdoors or in a well-ventilated area on a fireproof surface.
Keep a container of water or a fire extinguisher nearby in case of flare-ups.
Tie back long hair and secure loose clothing to avoid accidental ignition.
Do not touch the snake or sand until it has cooled fully, as they can remain hot.
Dispose of the cooled residue safely in household trash; do not attempt to reuse materials.

Questions to Consider

What gases help inflate and push up the snake? (Carbon dioxide and water vapor from sugar and baking soda decomposition.)
Why does the snake appear black? (It contains carbon formed from sugar breaking down without oxygen.)
What role does baking soda play in the reaction? (It decomposes to sodium carbonate, carbon dioxide, and water vapor, helping to produce gas that expands the snake.)
Why is sand used in this experiment? (It distributes heat evenly and slows the burn, allowing the snake to grow gradually instead of burning all at once.)