Sugar Dehydration
Convert sugar into carbon with sulfuric acid
Turn sugar into carbon by dehydrating sugar with strong sulfuric acid.
- 100 mL of 16 M sulfuric acid
- 85 g of granulated sugar
Perform demonstration in a well ventilated area.
- Add sulfuric acid to a beaker
- Add sugar to a beaker
- Stir the mixture completely
- Wait 2–3 minutes for reaction to complete
- Apparatus will be HOT. Do NOT touch until cool.
The sugar dehydration experiment (also known as the carbon snake experiment) is based on the ability of concentrated sulfuric acid to dehydrate sugar via the following process:
$$\mathrm{C_{12}H_{22}O_{11}}(g) \longrightarrow 12\mathrm{C}(s, \mathrm{~graphite}) + 11\mathrm{H_2O}(l)$$
We see sugar is converted to solid, black graphite and water is a product (hence dehydration).
When table sugar and concentrated sulfuric acid are combined, an exothermic reaction occurs that produces vaporized water and carbon dioxide. The vaporized water and carbon dioxide are responsible for the expansion of the mixture inside the container. As water and carbon dioxide are produced, the mixture becomes inflated and expands beyond the opening of its container, creating a snake-like appearance. The overall chemical equation can be seen below.
$$\mathrm{C_{12}H_{22}O_{11}}(g) + \mathrm{H_2SO_4}(aq) + \dfrac{1}{2}\mathrm{O_2}(g) \longrightarrow 11\mathrm{C}(s) + \mathrm{CO_2}(g) + 12\mathrm{H_2O}(g) + \mathrm{SO_2}(g) + \mathrm{heat}$$
If you look closely, you can see steam coming off the column of graphite!
Eric Van Dornshuld
Assistant clinical professor.
Faculty advisor to the MSU SMACS (2016–present).
BEARDED SCIENCE GUY
How to do the sulfuric acid and sugar dehydration reaction.
YouTube Video
Watch the Sulfuric Acid and Sugar Experiment
SAFETY NOTE: Due to the nature of this experiment, it is best performed in a lab with a scientist or science educator.
Sulfuric Acid and Sugar Experiment Supply List
Small glass container
Granulated or powdered sugar
Concentrated sulfuric acid
Stirring stick
Don't forget your safety gear!
Safety goggles
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