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.)