Formation of iodine vapor under the action of alpha-pinene

Formation of a beautiful purple iodine vapor

Scientific name: The exothermic reaction between alpha-pinene and iodine causes the sublimation of iodine


Reaction of alpha-pinene with iodine

by ChemToddler

Turpentine + Iodine

by 12thealchemist


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Reaction formula

C10H16 + I2 → C10H16I2

Step-by-step instruction

WARNING! This experiment is dangerous! You should NOT perform this at home. ONLY carry out this experiment, if you are a trained chemist, and you understand local safety and legal requirements, which are required to perform such experiments

  1. Pour a small pile of crystalline iodine
  2. Add a drop of alpha-pinene to the center of the pile of iodine
  3. Observe the formation of iodine vapour

Scientific background

Alpha-pinene contains a double bond which allows it to react with iodine. The reaction takes place with a lot of rearrangements and is very exothermic. The generated heat causes the sublimation of iodine. Iodine vapor has a purple color.


Published on 30 April 2015

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