Testing the density of liquids

Overview

Why do some liquids sink and others float? The density of a liquid is impacted by the weight of the molecules and how closely they are packed together.

Chemicals

Materials

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*Note: These chemicals can be purchased locally at stores such as Walmart/Target.

  • 2 Test tubes

  • Test tube rack

  • Graduated cylinder

Procedure

In each test tube, fill with acetone or water and drop in food coloring.

1.

In the graduated cylinder, pour the liquids slowly in this order: Milk, Dish soap, Water, Vegetable oil, Acetone.

2.

Drop small items into the graduated cylinder to estimate their density (mini marshmallow, raisin, dried bean).

3.

The Science Behind the Reaction

Density measures how many molecules you can fit in one area.  The more you can fit, the more dense that liquid. Lighter (less dense) liquids will balance on top of heavier (more dense) liquids.

Keep Experimenting!

What happens when you switch up the order you add the liquids? Do they get to their "rightful positions" or react with each other, making a whole new liquid (I'm looking at you milk and acetone.)