Bleaching liquid

The dark liquid boils rapidly and when boiling stops it turns clear.

Scientific name: Oxidation reaction of isopropanol by permanganate ion proceeds with a great evolution of heat and solution color change.

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Обесцвечивание жидкости - химические опыты

by ПРОСТАЯ НАУКА

Safety

Wear eye protection goggles and gloves. This is a violent reaction. Keep a safe distance. There is a serious fire risk - a fire extinguisher should be ready.

Always follow general safety recommendations. Please note that conducting chemistry experiments you must comply with the relevant legal procedures in your country.

Reaction formula

2KMnO4 + 5CH3CHOHCH3 + 3H2SO4 → 2MnSO4 + 5CH3COCH3 + K2SO4 + 8H2O

Step-by-step instruction

  1. Prepare a large volumetric cylinder (500 ml).
  2. Pour 75 ml of H2SO4 solution.
  3. Add 75 ml of isopropanol. Pour it carefully along the cylinder’s wall.
  4. Drop about half a teaspoon of KMnO4 to the solution.
  5. When it is added to the isopropanol/H2SO4 mixture the liquid turns dark.
  6. When all components are mixed together the reaction starts. Move away until the reaction stops. It is very violent and proceeds with a great evolution of heat. It makes the solution boil. At the end of the reaction the solution becomes colorless.

Scientific background

In the considered experiment the oxidation reaction of isopropanol by permanganate ion is studied. Permanganate ions are a very intense purple color. If its concentration is high enough the solution looks dark. When potassium permanganate (KMnO4) is mixed together with sulfuric acid (H2SO4) and isopropanol (CH3CHOHCH3) a reaction begins.

2KMnO4 + 5CH3CHOHCH3 + 3H2SO4 → 2MnSO4 + 5CH3COCH3 + K2SO4 + 8H2O

The reaction is accompanied by evolution of a large amount of heat. The mixture boils rapidly. After the reaction is complete the solution turns clear since the products are colorless.

Danger:
Coolness:
Difficulty:

Published on 12 February 2015

  • Fire
  • Heating with fire
  • Explosion
  • Poisoned gas
  • Organic
  • Electricity
  • Solution
  • Oxidation reduction
  • Color change
  • Precipitate
  • Gassing
  • Catalyst