Colonne Arc-en-ciel de Densités

Empilement de liquides de densités différentes pour créer une colonne colorée

Classroom Demonstrations Beginner (Middle School) 30 min ~$8,00

Objectif

Démontrer le concept de densité des liquides en superposant des liquides non miscibles de densités différentes dans une grande colonne.

Contexte

Different liquids have different densities, and immiscible liquids will arrange themselves with the densest at the bottom and the least dense at the top. By carefully layering liquids such as honey, corn syrup, dish soap, water, vegetable oil, and rubbing alcohol, a dramatic rainbow column can be created. Small solid objects placed in the column float at the interface matching their density, further illustrating the concept.

Avertissements de sécurité

  • Rubbing alcohol is flammable — no open flames
  • Some liquids are sticky — clean spills immediately
  • Do not drink any of the layered liquids

EPI requis

goggles

Matériaux

  • Honey (50 mL)
    Density ≈ 1.42 g/mL
  • Corn syrup (50 mL)
    Density ≈ 1.38 g/mL
  • Maple syrup (50 mL)
    Density ≈ 1.32 g/mL
  • Dish soap (50 mL)
    Density ≈ 1.06 g/mL
  • Water (dyed blue) (50 mL)
    Density = 1.00 g/mL
  • Vegetable oil (50 mL)
    Density ≈ 0.92 g/mL
  • Rubbing alcohol (dyed red) (50 mL)
    Density ≈ 0.79 g/mL
  • Food coloring (Various)
    To distinguish water and alcohol layers

Équipement

Tall clear glass or graduated cylinder (500 mL) Funnel or turkey baster Small objects: grape, cherry tomato, ping pong ball, bolt, cork

Procédure

1

Start with the densest liquid: pour honey slowly into the bottom of the tall glass.

2 min
2

Tilt the glass slightly and pour corn syrup slowly down the side. It should form a distinct layer on top of the honey.

3 min
3

Continue adding layers in order of decreasing density: maple syrup, dish soap, blue-dyed water, vegetable oil, and red-dyed rubbing alcohol.

15 min Pour very slowly for clean layers
4

Observe the distinct layers. Gently drop small objects (grape, bolt, cork, ping pong ball) into the column and note where they settle.

5 min
5

Discuss why the layers form (density differences), why some are miscible and some immiscible, and why objects float at specific levels.

5 min

Résultats attendus

Seven distinct layers should be visible, creating a colorful rainbow column. A metal bolt sinks to the bottom, a grape rests on the corn syrup, a cherry tomato on the dish soap, and a ping pong ball floats on top. Cork floats on the water layer.

Nettoyage

Pour the column into a waste container (do not pour down the drain due to oil and syrup). Wash the glass with hot soapy water.

Détails

Catégorie
Classroom Demonstrations
Difficulté
Beginner (Middle School)
Durée
30 min
Coût estimé
$8,00
Étapes
5
Matériaux
8

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Frequently Asked Questions

What is the objective of Colonne Arc-en-ciel de Densités?
Démontrer le concept de densité des liquides en superposant des liquides non miscibles de densités différentes dans une grande colonne.
How difficult is Colonne Arc-en-ciel de Densités?
This experiment is rated as Beginner (Middle School). It takes approximately 30 minutes to complete.
What safety precautions are needed for Colonne Arc-en-ciel de Densités?
Key safety precautions include: Rubbing alcohol is flammable — no open flames; Some liquids are sticky — clean spills immediately; Do not drink any of the layered liquids.
What materials are needed for Colonne Arc-en-ciel de Densités?
The main materials required are: Honey, Corn syrup, Maple syrup, Dish soap, Water (dyed blue).
What results should I expect from Colonne Arc-en-ciel de Densités?
Seven distinct layers should be visible, creating a colorful rainbow column. A metal bolt sinks to the bottom, a grape rests on the corn syrup, a cherry tomato on the dish soap, and a ping pong ball floats on top. Cork floats on the water layer.