Salting Out—Density Bottle Demonstration Kit

Product Details

Two layers of beads are suspended in the middle of a bottle. Give the bottle a shake and the beads move to opposite ends. The beads then slowly move back to the starting position. How does this happen? Two liquid layers of differing densities create an interface in the middle of the bottle. When the bottle is shaken, a homogenous liquid mixture of uniform density is formed and the apparent densities of the beads can be observed. The attention-getting display is sure to generate questions and gives you a great lead-in for lessons on density, polarity, and solubility. Teacher Demonstration notes and student handouts are included. The bottle may be reused for years. Concepts: Density, non-polar vs. polar, solutions, immiscibility Time Required: 10 minutes Materials Provided: Plastic bottle, isopropyl alcohol, sodium chloride, and pony beads