Cristalização Fracionada de Sal e Areia

Separação de uma mistura usando diferenças de solubilidade

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

Objetivo

Separar uma mistura de sal e areia usando cristalização fracionada, demonstrando dissolução, filtração e cristalização por evaporação.

Contexto

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.

Avisos de segurança

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

EPI necessário

goggles

Materiais

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

Equipamentos

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

Procedimento

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

Resultados esperados

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.

Limpeza

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

Detalhes

Categoria
Crystallization
Dificuldade
Beginner (Middle School)
Duração
35 min
Custo estimado
$3,00
Passos
7
Materiais
2

Mais experimentos

Bala de Açúcar Cristalizado 25 min Cristalização de Salol (Salicilato de Fenila) 30 min Cultivo de Cristais de Alúmen 30 min Cultivo de Cristais de Bismuto Arco-Íris 45 min Cultivo de Cristais de Sulfato de Cobre 30 min Recristalização do Ácido Benzoico 45 min Supersaturação e Cristalização Instantânea 35 min

Frequently Asked Questions

What is the objective of Cristalização Fracionada de Sal e Areia?
Separar uma mistura de sal e areia usando cristalização fracionada, demonstrando dissolução, filtração e cristalização por evaporação.
How difficult is Cristalização Fracionada de Sal e Areia?
This experiment is rated as Beginner (Middle School). It takes approximately 35 minutes to complete.
What safety precautions are needed for Cristalização Fracionada de Sal e Areia?
Key safety precautions include: Handle hot evaporating dish with tongs; Do not heat to dryness too rapidly — spattering risk.
What materials are needed for Cristalização Fracionada de Sal e Areia?
The main materials required are: Salt-sand mixture, Distilled water.
What results should I expect from Cristalização Fracionada de Sal e Areia?
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.