How to Make Snow Crystals With Borax

Snowflakes are formed from the crystallization of water.

Many chemistry teachers demonstrate the process of crystallization and supersaturation by growing crystals of borax on a pipe cleaner. Crafters can use the same technique to simulate snow crystals on decorations. When a compound dissolves in water, supersaturation occurs when more of that substance dissolves than technically should. Borax exhibits a solubility of 5.8 percent, or 5.8 grams per 100 milliliters of solution, near room temperature. At elevated temperatures, however, more borax will dissolve than at room temperature. And if the hot borax solution then cools back to room temperature, it becomes supersaturated. Supersaturated solutions are inherently unstable, and the excess borax will crystallize on any available rough surface--in this case, the fuzzy coating of a pipe cleaner.

Things You'll Need

• Measuring cup
• Small saucepan
• 2-3 tablespoons borax powder
• Small glass or drinking cup
• Pipe cleaners
• String
• Pencil

Instructions

1. Place 1 cup of water in a small saucepan and bring to a boil.

2. Add 3 tablespoons (one at a time, making sure each tablespoon is dissolved before adding the next) of borax to the boiling water and stir until dissolved. When all the borax has dissolved, transfer the solution to an empty cup or glass.

3. Bend a pipe cleaner into the desired shape, then tie a string to the pipe cleaner and tie the other end to the middle of a pencil.

4. Immerse the pipe cleaner in the borax solution and then place the pencil across the top of the glass or cup. Remove any slack from the string by twisting the pencil. The pipe cleaner should be suspended in the middle of the cup without touching the sides or bottom.

5. Allow the solution to sit overnight. Within 24 hours, a thick layer of "snow" crystals will have formed on the pipe cleaner.

Tips & Warnings

• Add the tablespoons of borax one at a time. If undissolved borax is observed in the pan after 2 tablespoons, then skip the third tablespoon. Undissolved crystals will act as "seeds" in the solution, causing crystals to form in the solution instead of on the pipe cleaner.

• If the borax crystallizes when you transfer it from the saucepan to the glass or cup, try preheating the cup with hot water before transferring the solution.

• Borax can be toxic if ingested in large quantities. Thoroughly wash with hot water all materials that come into contact with the borax. Materials contaminated with borax should not be used for food preparation.

References

• Purdue University: Borax Snow Crystals
• Michigan State University: Borax Crystals
• Clackamas University: Supersaturation
• Dial Corp: Material Safety Data Sheet--20 Mule Team Borax

Resources

• Harvard University: Supersaturation and Crystallization