Soğuk Paket Kimyası

Amonyum nitratın endotermik çözünmesini inceleme

Thermochemistry Beginner (Middle School) 20 dak ~$6,00

Hedef

Amonyum nitratın suda çözünmesi sırasındaki sıcaklık değişimini ölçmek; hazır soğuk paketlerde kullanılan endotermik çözünme sürecini göstermek.

Arka Plan

Ammonium nitrate dissolves endothermically in water, absorbing heat from the surroundings and causing a significant temperature drop. This principle is used in commercial instant cold packs for first aid. The dissolution has ΔH = +25.7 kJ/mol.

Güvenlik Uyarıları

  • Ammonium nitrate is an oxidizer — keep away from organic materials and heat
  • Do not mix with anything other than water for this experiment
  • Wear goggles

Gerekli KKD

goggles

Malzemeler

  • Ammonium nitrate (NH₄NO₃) (30 g)
    Or from a commercial cold pack
  • Distilled water (100 mL)
    Room temperature

Ekipman

Polystyrene cup calorimeter Thermometer Stirring rod Analytical balance

Prosedür

1

Add 100 mL of distilled water to the polystyrene cup calorimeter. Record the initial temperature.

3 dak
2

Weigh 30 g of ammonium nitrate.

2 dak Ammonium nitrate is an oxidizer
3

Add the ammonium nitrate to the water. Stir gently to dissolve.

3 dak
4

Record the temperature every 30 seconds as it drops. Note the minimum temperature.

5 dak
5

Feel the outside of the cup — it should feel cold.

1 dak
6

Calculate ΔH of dissolution per mole: q = mcΔT, n = mass/M(NH₄NO₃), ΔH = q/n.

5 dak

Beklenen Sonuçlar

Temperature should drop 15-20°C. 30 g NH₄NO₃ = 0.375 mol. q = 100 × 4.18 × ΔT. Calculated ΔH should be approximately +25 kJ/mol (±15%).

Temizlik

The ammonium nitrate solution is safe to dispose down the drain (dilute). Rinse the calorimeter.

Ayrıntılar

Kategori
Thermochemistry
Zorluk
Beginner (Middle School)
Süre
20 dak
Tahmini Maliyet
$6,00
Adımlar
6
Malzemeler
2

Daha Fazla Deney

Bomba Kalorimetresi Simülasyonu 45 min Buzun Erime Entalpisi 25 min Çözünme Her Zaman Ekzotermik Değildir 25 min Endotermik Tepkime Gösterisi 20 min Hess Yasasının Doğrulanması 60 min Kahve Kupası Kalorimetresi 40 min Magnezyumun Yanma Isısı 50 min Metallerin Özgül Isı Kapasitesi 40 min Sodyum Asetatın Ekzotermik Kristallenmesi 30 min

Frequently Asked Questions

What is the objective of Soğuk Paket Kimyası?
Amonyum nitratın suda çözünmesi sırasındaki sıcaklık değişimini ölçmek; hazır soğuk paketlerde kullanılan endotermik çözünme sürecini göstermek.
How difficult is Soğuk Paket Kimyası?
This experiment is rated as Beginner (Middle School). It takes approximately 20 minutes to complete.
What safety precautions are needed for Soğuk Paket Kimyası?
Key safety precautions include: Ammonium nitrate is an oxidizer — keep away from organic materials and heat; Do not mix with anything other than water for this experiment; Wear goggles.
What materials are needed for Soğuk Paket Kimyası?
The main materials required are: Ammonium nitrate (NH₄NO₃), Distilled water.
What results should I expect from Soğuk Paket Kimyası?
Temperature should drop 15-20°C. 30 g NH₄NO₃ = 0.375 mol. q = 100 × 4.18 × ΔT. Calculated ΔH should be approximately +25 kJ/mol (±15%).