Burning of copper or lead Iodate with Urotropine

Formation of brown smoke

Scientific name: Oxidation of urotropine by copper or lead iodate


Горение смеси иодата меди или свинца с уротропином


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

Reaction formula

CuSO4 + 2 KIO3 → Cu(IO3)2 + K2SO4

Pb(NO3)2 + 2 KIO3 → Pb(IO3)2 + 2 KNO3

5 C6H12N4 + 18 Cu(IO3)2 → 18 CuO + 18 I2 + 30 CO2 + 30 H2O + 10 N2

5 C6H12N4 + 18 Pb(IO3)2 → 18 PbO + 18 I2 + 30 CO2 + 30 H2O + 10 N2

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. Obtain copper iodate and lead iodate. Add a saturated solution of potassium iodate to a saturated solution of copper sulfate and to a saturated solution of lead nitrate. Then, filter and dry the resulting precipitates at 250 degrees Celcius.
  2. Weigh 10 grams of copper iodate (or 13 grams of lead iodate) and 1 gram of hexamine.
  3. Mix both of the components and pour the mixture on the tile in a pile.
  4. Ingite the mixture.
  5. Observe the intense formation of brown smoke.

Scientific background

Iodate anion is a very strong oxidizer that can oxidize the nitrogen from amines to molecular nitrogen, in particular from hexamine. Smoke turns brown in the presence of excess of iodate, in the case of excess of hexamine smoke turns yellow because both of the compounds, iodine and hexamine, sublime.


Published on 13 June 2015

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