Poly Density Bottle

PIRA: 2B40.20

Materials: Poly Density Bottle

This demo is to show how density of different objects causes things to float on top of one another. The order goes isopropanol, white beads, blue beads, salt water from least dense to most dense. When shaking the bottle the alcohol and water mix causing the white beads to float to the top and blue beads to sink. However, the salt causes the alcohol and water to separate slowly. 

PREPARATION:

91% Isopropanol:

1. Remove the cap from the bottle containing extremely pure salt (NaCl), and both the white and blue beads
2. Add 400 ml of clean water, and recap. The water level will be about 11 cm (4.25 in) from the bottom of the bottle. Shake for several minutes until the water dissolves
3. Add 450 ml of 91% isopropanol alcohol and tightly recap. The liquid level will now be about 19 cm (7.3 in) from the bottom of the bottle.

70% Isopropanol:

1. Remove the cap from the bottle containing extremely pure salt (NaCl), and both the white and blue beads
2. Add 265 ml of clean water, and recap. The water level will be about 7.25 cm (2.85 in) from the bottom of the bottle. Shake for several minutes until the water dissolves
3. Add 585 ml of 70% isopropanol alcohol and tightly recap. The liquid level will now be about 19 cm (7.3 in) from the bottom of the bottle.