Fraktionierte Kristallisation von Salz und Sand

Trennung eines Gemisches durch Löslichkeitsunterschiede

Crystallization Beginner (Middle School) 35 Min. ~$3,00

Ziel

Ein Salz-Sand-Gemisch durch fraktionierte Kristallisation trennen und dabei Lösen, Filtration und Verdunstungskristallisation demonstrieren.

Hintergrund

This classic separation technique exploits the fact that salt dissolves in water while sand does not. The mixture is dissolved in hot water, filtered to remove sand, and then the salt is recovered by evaporation. This is fundamentally how salt has been harvested from seawater for millennia.

Sicherheitswarnungen

  • Handle hot evaporating dish with tongs
  • Do not heat to dryness too rapidly — spattering risk

Erforderliche PSA

goggles

Materialien

  • Salt-sand mixture (10 g)
    Pre-mixed approximately 50:50
  • Distilled water (100 mL)

Ausrüstung

250 mL beaker Filter paper Funnel Evaporating dish Hot plate Stirring rod Analytical balance

Durchführung

1

Weigh 10 g of the salt-sand mixture and record the mass.

2 Min.
2

Add the mixture to 100 mL of warm water in the beaker. Stir for 5 minutes to dissolve all the salt.

5 Min.
3

Filter the mixture through filter paper. The sand remains on the filter; the salt solution passes through.

5 Min.
4

Rinse the sand on the filter with a small amount of distilled water. Dry the sand and weigh it.

5 Min.
5

Pour the filtrate into the evaporating dish. Heat gently on the hot plate to evaporate the water.

12 Min. Remove from heat before completely dry
6

Once dry, weigh the recovered salt. Calculate the percentage of each component.

3 Min.
7

Compare the total recovered mass with the initial mass. Calculate percent recovery.

3 Min.

Erwartete Ergebnisse

The total mass of recovered salt + sand should be close to the original 10 g (typically 90-98% recovery). Some loss occurs during transfer and on filter paper. The separated components should be visually distinct.

Aufräumen

Salt solution can go down the drain. Sand can go in the trash. Rinse all glassware.

Details

Kategorie
Crystallization
Schwierigkeit
Beginner (Middle School)
Dauer
35 Min.
Geschätzte Kosten
$3,00
Schritte
7
Materialien
2

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Frequently Asked Questions

What is the objective of Fraktionierte Kristallisation von Salz und Sand?
Ein Salz-Sand-Gemisch durch fraktionierte Kristallisation trennen und dabei Lösen, Filtration und Verdunstungskristallisation demonstrieren.
How difficult is Fraktionierte Kristallisation von Salz und Sand?
This experiment is rated as Beginner (Middle School). It takes approximately 35 minutes to complete.
What safety precautions are needed for Fraktionierte Kristallisation von Salz und Sand?
Key safety precautions include: Handle hot evaporating dish with tongs; Do not heat to dryness too rapidly — spattering risk.
What materials are needed for Fraktionierte Kristallisation von Salz und Sand?
The main materials required are: Salt-sand mixture, Distilled water.
What results should I expect from Fraktionierte Kristallisation von Salz und Sand?
The total mass of recovered salt + sand should be close to the original 10 g (typically 90-98% recovery). Some loss occurs during transfer and on filter paper. The separated components should be visually distinct.