Density Column Lab - Part 2
Concluding a two-part lab activity, students use triple balance beams and graduated cylinders to take measurements and calculate densities of several household liquids and compare them to the densities of irregularly shaped objects (as determined in Part 1). Then they create density columns with the three liquids and four solid items to test their calculations and predictions of the different densities. Once their density columns are complete, students determine the effect of adding detergent to the columns. After this activity, present the associated Density & Miscibility lesson for a discussion about why the column layers do not mix.
A density column containing some common liquids and solids. From top: baby oil, rubbing alcohol (colored red), vegetable oil, wax, water (colored blue) and aluminum.Copyright 2008 PRHaney, Wikimedia Commons http://commons.wikimedia.org/wiki/File:Density_column.JPG
To monitor groundwater quality, and to clean water sources if necessary, it is vital to for environmental engineers to be familiar with the physical and chemical properties of the contaminants. Properties such as density and hydrophobicity must be considered when determining the best way to remediate contaminated sites. For example, the differing densities and immiscibilities of oil and water prove beneficial to engineers when cleaning oil spills.
After this activity, students should be able to:
- Explain the difference and relationship between mass and density.
- Take accurate measurements of mass and volume using a triple balance beam and reading a meniscus, respectively.
- Relate hydrophobicity and miscibility to density.