Endotermik Tepkime Gösterisi

Baryum hidroksit ve amonyum tiyosiyanatın soğuk tepkimesi

Thermochemistry Intermediate (High School) 20 dak ~$12,00

Hedef

Karışımın kolbun dışındaki suyu donduracak kadar soğuduğu dramatik bir endotermik tepkimeyi göstermek.

Arka Plan

When barium hydroxide octahydrate reacts with ammonium thiocyanate, the temperature drops to approximately -20°C. This endothermic reaction absorbs so much heat from the surroundings that water on the outside of the flask freezes, effectively gluing the flask to a wet board.

Güvenlik Uyarıları

  • Barium compounds are toxic if ingested
  • Ammonia gas is released — work in fume hood or ventilated area
  • Wear gloves when handling barium hydroxide
  • Do not inhale the ammonia fumes

Gerekli KKD

goggles gloves lab_coat

Malzemeler

  • Barium hydroxide octahydrate (32 g)
    Toxic
  • Ammonium thiocyanate (16 g)
  • Water (5 mL)
    On the board

Ekipman

250 mL Erlenmeyer flask Wooden board Thermometer Stirring rod

Prosedür

1

Pour a few drops of water onto the wooden board to create a wet spot.

1 dak
2

Add 32 g barium hydroxide octahydrate to the flask.

2 dak Wear gloves — barium is toxic
3

Add 16 g ammonium thiocyanate to the flask. Stir the mixture with a glass rod.

2 dak Ammonia released — ventilation
4

Place the flask on the wet spot on the board. Insert the thermometer.

1 dak
5

Observe the temperature dropping dramatically. Record the minimum temperature.

5 dak Do not inhale fumes
6

After 5 minutes, try to lift the flask. It should be frozen to the board.

2 dak
7

Explain that the reaction absorbed heat from the surroundings, freezing the water beneath.

2 dak

Beklenen Sonuçlar

The temperature should drop to approximately -20°C within minutes. The flask should freeze to the wet board. A strong smell of ammonia confirms the reaction is proceeding.

Temizlik

Allow to warm to room temperature. Dispose of barium waste in heavy metal waste container. Rinse flask and ventilate area thoroughly.

Ayrıntılar

Kategori
Thermochemistry
Zorluk
Intermediate (High School)
Süre
20 dak
Tahmini Maliyet
$12,00
Adımlar
7
Malzemeler
3

Daha Fazla Deney

Bomba Kalorimetresi Simülasyonu 45 min Buzun Erime Entalpisi 25 min Çözünme Her Zaman Ekzotermik Değildir 25 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 Soğuk Paket Kimyası 20 min

Frequently Asked Questions

What is the objective of Endotermik Tepkime Gösterisi?
Karışımın kolbun dışındaki suyu donduracak kadar soğuduğu dramatik bir endotermik tepkimeyi göstermek.
How difficult is Endotermik Tepkime Gösterisi?
This experiment is rated as Intermediate (High School). It takes approximately 20 minutes to complete.
What safety precautions are needed for Endotermik Tepkime Gösterisi?
Key safety precautions include: Barium compounds are toxic if ingested; Ammonia gas is released — work in fume hood or ventilated area; Wear gloves when handling barium hydroxide.
What materials are needed for Endotermik Tepkime Gösterisi?
The main materials required are: Barium hydroxide octahydrate, Ammonium thiocyanate, Water.
What results should I expect from Endotermik Tepkime Gösterisi?
The temperature should drop to approximately -20°C within minutes. The flask should freeze to the wet board. A strong smell of ammonia confirms the reaction is proceeding.