How to Burn a Sugar Cube

Sugar cubes will not burn on their own.

A simple science experiment, burning a sugar cube can be done as a class experiment or outside project. A sugar cube will not burn on its own, and the process of burning a sugar cube allows a teacher to demonstrate the concept of catalysts. A sugar cube will melt, which is a physical change, but will not undergo the chemical change of combustion without assistance. Burning a sugar cube can also open up discussion about the difference between chemical and physical changes.

Things You'll Need

• Tongs
• Lighter or match
• Sugar cube
• Ashes
• Water or fire extinguisher

Instructions

1. Pick up a sugar cube with the tongs.

2. Hold the sugar cube over a lit match or lighter. The sugar will melt, but will not burn. Touch the sugar cube to the flame to demonstrate.

3. Pick up another sugar cube with the tongs. Rub one side of it with ashes.

4. Hold the ash-rubbed side of the sugar cube over the flame. The sugar cube will ignite.

Tips & Warnings

• You can use cigarette ashes found in an ashtray or burn a piece of paper or wood to get the ashes.

• Keep a bucket of water or fire extinguisher on hand when experimenting with fire. Never conduct a fire experiment without adult supervision.

References

• Princeton Materials Institute K-12 Outreach: Supplementary Extensions
• Chemistry at Indiana University Chemistry Demos: Ash Catalyzes the Combustion of Sugar
• Rader's Chem4Kids: Chemical vs. Physical Changes