코끼리 치약

과산화수소의 빠른 촉매 분해로 거대한 거품 기둥 생성

Classroom Demonstrations Beginner (Middle School) 20 분 ~$10.00

목표

아이오딘화칼륨을 이용한 과산화수소의 촉매 분해를 실증하고, 촉매 작용·발열 반응·기체 발생의 개념을 설명한다.

배경

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.

안전 경고

  • 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

필수 개인 보호 장비

goggles gloves lab_coat face_shield

재료

  • 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

장비

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

실험 절차

1

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

2 분 Ensure audience is at safe distance
2

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

2 분 30% H₂O₂ is extremely corrosive
3

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

2 분
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 분 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 분
6

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

5 분 Wait until foam is cool

예상 결과

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).

정리

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

세부 정보

카테고리
Classroom Demonstrations
난이도
Beginner (Middle School)
소요 시간
20 분
예상 비용
$10.00
단계
6
재료
5

더 많은 실험

드라이아이스 속 마그네슘 연소 25 min 진동하는 브릭스-라우처 반응 40 min 나트륨과 물의 반응 25 min 아이오딘 시계 반응 45 min 사라지는 비커(굴절률 매칭) 15 min 테르밋 반응 30 min 루미놀 화학발광 30 min 비뉴턴 유체: 우블렉 20 min 밀도 컬럼 무지개 30 min 순간 냉동: 과냉각수 120 min

Frequently Asked Questions

What is the objective of 코끼리 치약?
아이오딘화칼륨을 이용한 과산화수소의 촉매 분해를 실증하고, 촉매 작용·발열 반응·기체 발생의 개념을 설명한다.
How difficult is 코끼리 치약?
This experiment is rated as Beginner (Middle School). It takes approximately 20 minutes to complete.
What safety precautions are needed for 코끼리 치약?
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 코끼리 치약?
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 코끼리 치약?
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).