Sugar and Sulfuric Acid Carbon Snake

Materials: ★★☆ Available in most school laboratories or specialist stores
Difficulty: ★★☆ Can be done by science teachers
Safety: ★★☆ Some safety precautions required to perform safely

Categories: Chemical Reactions, Compounds, Elements and Periodic Table

Alternative titles: Black Snake Experiment

Summary

Concentrated sulfuric acid is added to sugar, causing a vigorous dehydration and oxidation reaction. The mixture heats up and produces steam, carbon dioxide, and a growing black column of carbon that resembles a snake rising from the container.

Procedure

Fill a small beaker about two-thirds full with sugar.
Carefully pour 10–15 ml of concentrated sulfuric acid onto the sugar.
Wait and observe as the reaction generates heat and a black carbon mass rises out of the beaker.

Links

H2SO4 and Sugar (Carbon Snake) - MrLeavittScience:

📄 “Carbon snake” experiment - MEL Science: https://melscience.com/AU-en/articles/carbon-snake-experiment/?srsltid=AfmBOorFTI7ugDBb0ltD7wP0WYLO0gLWb2WaccaLAw0zFqKHpI3M-Eum

📄 Carbon Snake - UC San Diego: https://www-chem.ucsd.edu/undergraduate/teaching-labs/demos/demo31.html

Variations

Try using different container sizes to produce snakes of varying shapes.
Use food coloring in the sugar for visual effects before the reaction begins.

Safety Precautions

Wear safety glasses and gloves.
Perform the experiment in a fume hood or well-ventilated area.
Avoid skin or clothing contact with sulfuric acid.
Be cautious of intense heat generated during the reaction.
Conduct only under professional supervision.

Questions to Consider

Why does sulfuric acid cause sugar to blacken and expand? (It dehydrates sugar, removing water and leaving behind carbon.)
What gases are released during the reaction? (Primarily water vapor and carbon dioxide.)
Why must this experiment be performed in a fume hood? (The reaction releases gases and vapors that may be harmful in enclosed spaces.)