अतिसंतृप्ति और तात्कालिक क्रिस्टलीकरण

सोडियम एसीटेट में तत्काल क्रिस्टल निर्माण को ट्रिगर करना

Crystallization Intermediate (High School) 35 मिनट ~$8.00

उद्देश्य

एक अतिसंतृप्त सोडियम एसीटेट विलयन तैयार करें और तात्कालिक क्रिस्टलीकरण को ट्रिगर करें, अस्थिर अतिसंतृप्ति और ऊष्माक्षेपी क्रिस्टलीकरण (गर्म बर्फ) प्रदर्शित करें।

पृष्ठभूमि

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.

सुरक्षा चेतावनियाँ

  • 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

आवश्यक PPE

goggles

सामग्री

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

उपकरण

250 mL beaker or flask Hot plate Stirring rod Thermometer

प्रक्रिया

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 मिनट Handle hot solution carefully
2

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

15 मिनट
3

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

2 मिनट
4

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

2 मिनट
5

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

2 मिनट Crystals will be warm
6

The process is reversible — reheat to dissolve and repeat.

5 मिनट

अपेक्षित परिणाम

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.

सफाई

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

विवरण

श्रेणी
Crystallization
कठिनाई
Intermediate (High School)
अवधि
35 मिनट
अनुमानित लागत
$8.00
चरण
6
सामग्री
2

अधिक प्रयोग

कॉपर सल्फेट क्रिस्टल उगाना 30 min चीनी क्रिस्टल रॉक कैंडी 25 min नमक और रेत का खंडित क्रिस्टलीकरण 35 min फिटकरी क्रिस्टल उगाना 30 min बिस्मथ इंद्रधनुष क्रिस्टल उगाना 45 min बेंजोइक अम्ल का पुनःक्रिस्टलीकरण 45 min सैलोल (फेनाइल सैलिसिलेट) का क्रिस्टलीकरण 30 min

Frequently Asked Questions

What is the objective of अतिसंतृप्ति और तात्कालिक क्रिस्टलीकरण?
एक अतिसंतृप्त सोडियम एसीटेट विलयन तैयार करें और तात्कालिक क्रिस्टलीकरण को ट्रिगर करें, अस्थिर अतिसंतृप्ति और ऊष्माक्षेपी क्रिस्टलीकरण (गर्म बर्फ) प्रदर्शित करें।
How difficult is अतिसंतृप्ति और तात्कालिक क्रिस्टलीकरण?
This experiment is rated as Intermediate (High School). It takes approximately 35 minutes to complete.
What safety precautions are needed for अतिसंतृप्ति और तात्कालिक क्रिस्टलीकरण?
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 अतिसंतृप्ति और तात्कालिक क्रिस्टलीकरण?
The main materials required are: Sodium acetate trihydrate, Distilled water.
What results should I expect from अतिसंतृप्ति और तात्कालिक क्रिस्टलीकरण?
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.