Lewat Jenuh dan Kristalisasi Seketika

Memicu pembentukan kristal seketika dalam natrium asetat

Crystallization Intermediate (High School) 35 menit ~$8,00

Tujuan

Siapkan larutan natrium asetat lewat jenuh dan picu kristalisasi seketika, mendemonstrasikan lewat jenuh metastabil dan kristalisasi eksotermik (es panas).

Latar Belakang

Sodium acetate trihydrate can form extremely supersaturated solutions that remain liquid until disturbed. Adding a single seed crystal or scratching the container wall triggers rapid crystallization throughout the solution, releasing heat (exothermic). The resulting solid resembles ice but is warm to the touch.

Peringatan Keselamatan

  • The solution gets hot when it crystallizes — handle with care
  • Sodium acetate is generally safe but avoid ingestion
  • Use heat-resistant gloves when handling hot solution

APD yang Diperlukan

goggles

Bahan

  • Sodium acetate trihydrate (100 g)
    Or make from vinegar + baking soda
  • Distilled water (10 mL)
    Minimal amount

Peralatan

250 mL beaker or flask Hot plate Stirring rod Thermometer

Prosedur

1

Add 100 g sodium acetate trihydrate and 10 mL water to the beaker. Heat while stirring until all crystals dissolve (about 70°C).

8 menit Handle hot solution carefully
2

Remove from heat and allow to cool to room temperature undisturbed. Do not shake or add anything.

15 menit
3

Once cooled, the solution should remain liquid despite being supersaturated. Measure the temperature.

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4

Drop a single small crystal of sodium acetate into the solution and observe the rapid crystallization wave.

2 menit
5

Immediately measure the temperature of the newly formed crystals. Note the temperature increase (exothermic).

2 menit Crystals will be warm
6

The process is reversible — reheat to dissolve and repeat.

5 menit

Hasil yang Diharapkan

When triggered, crystallization should sweep through the solution in seconds, forming a solid mass of warm crystals (hence "hot ice"). The temperature typically rises 10-20°C above room temperature. This is the principle behind reusable hand warmers.

Pembersihan

Sodium acetate is reusable. Simply reheat to dissolve. Can be disposed down the drain. Rinse equipment.

Detail

Kategori
Crystallization
Tingkat Kesulitan
Intermediate (High School)
Durasi
35 menit
Perkiraan Biaya
$8,00
Langkah
6
Bahan
2

Eksperimen Lainnya

Kristalisasi Fraksional Garam dan Pasir 35 min Kristalisasi Salol (Fenil Salisilat) 30 min Menumbuhkan Kristal Pelangi Bismut 45 min Menumbuhkan Kristal Tawas 30 min Menumbuhkan Kristal Tembaga Sulfat 30 min Permen Batu Kristal Gula 25 min Rekristalisasi Asam Benzoat 45 min

Frequently Asked Questions

What is the objective of Lewat Jenuh dan Kristalisasi Seketika?
Siapkan larutan natrium asetat lewat jenuh dan picu kristalisasi seketika, mendemonstrasikan lewat jenuh metastabil dan kristalisasi eksotermik (es panas).
How difficult is Lewat Jenuh dan Kristalisasi Seketika?
This experiment is rated as Intermediate (High School). It takes approximately 35 minutes to complete.
What safety precautions are needed for Lewat Jenuh dan Kristalisasi Seketika?
Key safety precautions include: The solution gets hot when it crystallizes — handle with care; Sodium acetate is generally safe but avoid ingestion; Use heat-resistant gloves when handling hot solution.
What materials are needed for Lewat Jenuh dan Kristalisasi Seketika?
The main materials required are: Sodium acetate trihydrate, Distilled water.
What results should I expect from Lewat Jenuh dan Kristalisasi Seketika?
When triggered, crystallization should sweep through the solution in seconds, forming a solid mass of warm crystals (hence "hot ice"). The temperature typically rises 10-20°C above room temperature. This is the principle behind reusable hand warmers.