Pasta Gigi Gajah

Dekomposisi katalitik cepat hidrogen peroksida menghasilkan kolom busa besar

Classroom Demonstrations Beginner (Middle School) 20 menit ~$10,00

Tujuan

Demonstrasikan dekomposisi katalitik hidrogen peroksida menggunakan kalium iodida, menggambarkan konsep katalisis, reaksi eksotermik, dan evolusi gas.

Latar Belakang

Elephant toothpaste is one of the most popular chemistry demonstrations. Concentrated hydrogen peroxide (H₂O₂) is decomposed rapidly by a potassium iodide (KI) catalyst, releasing oxygen gas and steam. When performed in a narrow-neck flask with dish soap, the oxygen gas creates a towering column of foam that erupts like giant toothpaste. The reaction is exothermic, and the foam is warm to the touch. The iodide ion acts as a catalyst by cycling between I⁻ and IO⁻ intermediates.

Peringatan Keselamatan

  • 30% H₂O₂ causes severe skin burns and eye damage
  • Wear face shield and heavy-duty gloves
  • Do not stand over the flask when adding KI
  • The foam is hot — do not touch immediately
  • Perform behind a safety shield

APD yang Diperlukan

goggles gloves lab_coat face_shield

Bahan

  • Hydrogen peroxide (30%) (50 mL)
    30% concentration required for dramatic effect
  • Potassium iodide (KI) (10 g)
    Dissolved in 25 mL water
  • Liquid dish soap (15 mL)
  • Food coloring (5 drops)
    Optional, for visual effect
  • Large tray or bin (1)
    To catch overflow

Peralatan

Erlenmeyer flask (1 L, narrow neck) Measuring cylinder Safety shield or splash guard Funnel

Prosedur

1

Place the Erlenmeyer flask on the large tray. Set up the safety shield.

2 menit Ensure audience is at safe distance
2

Carefully pour 50 mL of 30% H₂O₂ into the flask.

2 menit 30% H₂O₂ is extremely corrosive
3

Add 15 mL of dish soap and a few drops of food coloring. Swirl gently to mix.

2 menit
4

Dissolve 10 g of KI in 25 mL of warm water. Pour this solution into the flask using a funnel and step back immediately.

2 menit Step back immediately after adding
5

Observe the rapid evolution of foam. The reaction is complete in seconds. Discuss the role of KI as a catalyst.

5 menit
6

After the foam cools, students may touch it (with gloves). It contains only water, oxygen, soap, and KI — no H₂O₂ remains.

5 menit Wait until foam is cool

Hasil yang Diharapkan

A dramatic eruption of warm, colored foam that rises 1–2 meters above the flask. Steam may be visible. The reaction demonstrates catalysis (KI is not consumed), exothermic processes, and gas evolution (O₂).

Pembersihan

The foam is non-toxic (soap, water, KI). Rinse down the drain with plenty of water. Clean the flask and tray.

Detail

Kategori
Classroom Demonstrations
Tingkat Kesulitan
Beginner (Middle School)
Durasi
20 menit
Perkiraan Biaya
$10,00
Langkah
6
Bahan
5

Eksperimen Lainnya

Cairan Non-Newton: Ooblek 20 min Gelas Kimia yang Menghilang (Pencocokan Indeks Bias) 15 min Kemiluminensensi dengan Luminol 30 min Kolom Kerapatan Pelangi 30 min Pembakaran Magnesium dalam Es Kering 25 min Pembekuan Seketika: Air Superdingin 120 min Reaksi Jam Iodin 45 min Reaksi Natrium dan Air 25 min Reaksi Osilasi Briggs-Rauscher 40 min Reaksi Termit 30 min

Frequently Asked Questions

What is the objective of Pasta Gigi Gajah?
Demonstrasikan dekomposisi katalitik hidrogen peroksida menggunakan kalium iodida, menggambarkan konsep katalisis, reaksi eksotermik, dan evolusi gas.
How difficult is Pasta Gigi Gajah?
This experiment is rated as Beginner (Middle School). It takes approximately 20 minutes to complete.
What safety precautions are needed for Pasta Gigi Gajah?
Key safety precautions include: 30% H₂O₂ causes severe skin burns and eye damage; Wear face shield and heavy-duty gloves; Do not stand over the flask when adding KI.
What materials are needed for Pasta Gigi Gajah?
The main materials required are: Hydrogen peroxide (30%), Potassium iodide (KI), Liquid dish soap, Food coloring, Large tray or bin.
What results should I expect from Pasta Gigi Gajah?
A dramatic eruption of warm, colored foam that rises 1–2 meters above the flask. Steam may be visible. The reaction demonstrates catalysis (KI is not consumed), exothermic processes, and gas evolution (O₂).