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Procedure:
1. Pour 50 mL of syrup into a 250 mL glass graduated cylinder and let the liquid settle.
2. Tilt the graduated cylinder and pour 50 mL of dishwashing detergent slowly down the side of the cylinder. Then, let the liquid
settle in the upright position. The detergent should form a layer on top of the syrup.
3. Repeat step 2 for the other liquids: red-colored water, vegetable oil, and blue-colored alcohol.
4. Drop in various items (ice, cork, chalk) and observe the level at which the object sinks or floats.
5. Cover the cylinder in plastic wrap and leave it undisturbed for several days before re-examining.
6. Shake the graduated cylinder and re-examine after several minutes.
Expected Results:
The column is made by pouring the heaviest liquid into the glass first, followed by the next-heaviest liquid, etc. The heaviest
liquid has the most mass per unit volume or the highest density. The colored liquids layer in the column (from bottom to top:
brown, green, red, yellow, blue).
Follow up/Extension:
1. Why did we use the graduated cylinder? What did that help us measure?
2. Why did we add the objects? How did they impact the total volume?
3. Can liquids have different densities, like solid objects?
4. What differences did you notice between where each object (the ice, chalk, and cork) sank? What explains those differences?
5. How do density and mass help explain your observations?
• Use a triple beam balance for further measurements and investigations.
• Change some of the variables like water temperature, objects used, size of objects, liquids used.
• How do these concepts help explain Earth Science lessons about the density of sedimentary rocks compared to
metamorphic rocks?
Teaching notes:
• Except for the oil, the liquids are miscible, so care must be taken when layering them.
• Students could determine the densities of the liquids to generate the order of pouring the liquids.
Disposal/Clean-Up:
Contents of the cylinder can be safely poured down the drain but ensure that solids are strained out or removed from the sink
trap and placed in the garbage.
Density Columns (continued)
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