Kitchen Chemistry Experiment 17
Daffy Densities

All materials have characteristic densities. As long as the materials do not mix or react the less dense materials will float on the more dense layer. This activity can be done as a lab or demonstration and uses 4 solids and 6 liquids to create a colorful column.

Materials	Substitutions
1 large test tube	1 large vase or graduated cylinder
ethanol ( green )	rubbing alcohol ( green )
liquid dishwashing detergent
dark corn syrup
vegetable oil
glycerine
water( red ) & food-coloring
OPTIONAL SOLIDS:
cork stopper	fishing cork bobber
solid rubber stopper	rubber SUPERBALL or jacks ball
1 small block of oak wood
1 small piece of lead	a lead sinker

Procedure

1. Slowly pour the following liquids into a narrow, clear glass container in this order:

• dark Karo syrup ( pour this one straight down! ),
• glycerine,
• Dawn dishwashing liquid (blue),
• water ( with red food coloring added ),
• vegetable oil (yellow),
• rubbing alcohol ( with green food coloring added ).

Pour carefully so that layers will form. (See illustration).

2. Observe what happens as you add small samples of the solids listed above. Try to avoid mixing the layers when adding the solids.

Teacher's Notes

1. Try adding some of the following solids to note their comparative densities:
   • a drip of candle wax
   • a wooden toothpick
   • a small block of pine
   • an ice cube
   • a new penny (>1986)
2. Students can complete this as a laboratory exercise. If given some densities as 'knowns', then they should be able to set approximate ranges for the other materials.