Züchtung von Alaun-Kristallen

Herstellung großer transparenter Alaun-Kristalle

Crystallization Beginner (Middle School) 30 Min. ~$6,00

Ziel

Große, transparente oktaedrische Kaliumalaun-Kristalle aus einer übersättigten Lösung züchten.

Hintergrund

Potassium alum (KAl(SO₄)₂·12H₂O) crystallizes in a beautiful octahedral habit. It is non-toxic, inexpensive, and easy to grow into large crystals. The octahedral shape reflects the cubic crystal system of alum.

Sicherheitswarnungen

  • Use care with hot water
  • Alum is generally safe but avoid ingestion of large amounts

Erforderliche PSA

goggles

Materialien

  • Potassium alum (100 g)
    Food-grade available
  • Distilled water (300 mL)
    Hot
  • Thread or monofilament (30 cm)

Ausrüstung

500 mL beaker Hot plate Stirring rod Pencil Filter paper

Durchführung

1

Heat 300 mL of distilled water to near boiling. Slowly dissolve as much alum as possible (about 80-100 g) while stirring.

10 Min. Handle hot liquids carefully
2

Filter the hot solution to remove any undissolved particles.

3 Min.
3

Pour a small amount into a dish and let it cool to form seed crystals overnight.

2 Min.
4

Select the best octahedral seed crystal. Tie it to thread and suspend in the main solution.

5 Min.
5

Cover loosely and store in a stable, cool location. Check daily.

2 Min.
6

After 1-2 weeks, remove the crystal, dry with a paper towel, and photograph the octahedral faces.

5 Min.

Erwartete Ergebnisse

Large, transparent, octahedral crystals up to 2-4 cm across after 1-2 weeks. The faces should be smooth and the crystal should be nearly colorless and transparent.

Aufräumen

Alum solution can be saved for future crystal growing or disposed down the drain. Rinse beaker.

Details

Kategorie
Crystallization
Schwierigkeit
Beginner (Middle School)
Dauer
30 Min.
Geschätzte Kosten
$6,00
Schritte
6
Materialien
3

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Frequently Asked Questions

What is the objective of Züchtung von Alaun-Kristallen?
Große, transparente oktaedrische Kaliumalaun-Kristalle aus einer übersättigten Lösung züchten.
How difficult is Züchtung von Alaun-Kristallen?
This experiment is rated as Beginner (Middle School). It takes approximately 30 minutes to complete.
What safety precautions are needed for Züchtung von Alaun-Kristallen?
Key safety precautions include: Use care with hot water; Alum is generally safe but avoid ingestion of large amounts.
What materials are needed for Züchtung von Alaun-Kristallen?
The main materials required are: Potassium alum, Distilled water, Thread or monofilament.
What results should I expect from Züchtung von Alaun-Kristallen?
Large, transparent, octahedral crystals up to 2-4 cm across after 1-2 weeks. The faces should be smooth and the crystal should be nearly colorless and transparent.