Crystals

Concept: Capillary Action
Capillary action describes the spontaneous flow of a liquid into a narrow tube or porous material. It is caused by the combination of the cohesive forces of the liquid and the adhesive forces between the liquid and the narrow tube or porous material. These forces pull the liquid into the tube. This is how plants bring water up through their roots to their stem and leaves.

Read Aloud: Cool Chemistry Concoctions by Joe Rhatigan

Ingredients:

      ·         1 tbl. Water

      ·         1 tbl. Salt

      ·         1 tbl. Liquid Bluing (Mrs. Stewart's Brand)

      ·         ½ tbl. Ammonia

      ·         Plastic Bottle
      ·         Paper Bowl
      ·         Toilet Paper Tube

 Demonstration:

      ·         Mix together 1 tablespoon of water, 1 tablespoon of salt, 1 tablespoon of liquid bluing and ½ tablespoon of ammonia in a plastic bottle.
      ·         Pour the solution from the plastic bottle into a paper bowl.
      ·         Use food coloring to dye the surface of a toilet paper tube.

      ·         Place the toilet paper tube in the center of the paper bowl. The bottom of the tube should be submerged in the solution.

      ·         Wait and watch as crystals begin to form.

Experiment:

·         What happens if the toilet paper tube is not dyed with food coloring?

·         What happens if a PVC tube is used in place of the toilet paper tube?

Observations:
Capillary action draws the liquid solution up into the toilet paper tube. Once the toilet paper tube has been soaked in the solution, the solution begins to evaporate. The evaporation process is accelerated by the ammonia, which evaporates more quickly than water. As the water from the solution evaporates with the help of the ammonia, the dissolved salt begins to crystallize around the particles left by the bluing.