Chemistry Thought Of The Day: Holiday Fun – Snowflakes

StickFigure-BoomDIY: Snowflakes

TOOLS:

  • String
  • Wide-mouth mason jar
  • Pipe Cleaners
  • Borax (Look in laundry section of grocery)
  • Pencil / Clothes Pins
  • Water
  • Food Coloring (optional)

PROCEDURE:

  1. Form pipe cleaners into whatever festive shape you'd like.  Make sure that it will fit into the jar.
  2. Tie one end of the string to the pipe cleaner and the other end to the pencil.
  3. Boil water and fill jar until it is a bit over 3/4 full.
  4. Add borox to water 1 tbsp. at a time and stir to dissolve (approximately 3 tbsp. per cup of water)
  5. Tint water with food color if desired
  6. Placing the pencil across the mouth of the jar, ensure that the shape is fully submerged in the liquid, but not touching the bottom or sides
  7. Leave undisturbed for 24-48 hours and watch crystal form

CAUTION(s):

  • Boiling water can cause burns
  • Borox *SHOULD NOT* be ingested

THE SCIENCE:

This experiment demonstrates the precipitation of crystals from a super saturated solution.  As borox is added to the water it begins to dissolve and as the water is heated, more borox is able to be dissolved into the solution.  When no more is able to be dissolved, the solution becomes saturated.  As the water cools, the molecules of the water are less active and move closer together causing some of the borox crystals to precipitate out into the visible crystals.  The pipe cleaner acts as a nucleation point for the crystals to form and as the water cools / evaporates, the crystals build further upon each other.

NB:

This same process can be used to make rock candy (obviously without the borox).  Instead of pipe cleaners and laundry detergent, you could use chopsticks and ~3 cups of sugar per cup of water.

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