Magic Jug

One solution is poured into six different glasses and they become different colors

Scientific name: Solution of NH4Fe(SO4)2*12H2O reacts with SCN-, Ba2+, [Fe(CN)6]3-, HSO3- ions, tannic and tartaric acid

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Safety

Wear lab gloves and eye protection.

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

Reaction formula

Fe3+ + SCN- → [Fe(SCN)]2+

Ba2+ + SO42- → BaSO4

Fe3+ + [Fe(CN)6]3- → Fe[Fe(CN)6]

Fe3+ + C76H52O46 (tannic acid) → Ferrum tanates

Fe3+ + C4H6O6 (tartaric acid) → Fe2(C4H4O6)3

Fe3+ + 3HSO3- → Fe(HSO3)3

Step-by-step instruction

  1. Prepare six glasses containing a small amount of six solutions: potassium thiocyanate, barium chloride, potassium ferricyanide, tannic acid, tartaric acid and sodium bisulfite.
  2. Prepare a solution of ammonium iron(III) sulfate in a jug.
  3. Pour the solution from the jug into the glasses.

Scientific background

The solution of ammonium iron(III) sulfate contains Fe3+ and SO42- ions. There are thiocyanate, barium, ferricyanide, sulfide ions, tannic and tartaric acids in the glasses.

Potassium thiocyanate reacts with Fe3+ ions and forms a dark-red colored solution, which contains [Fe(SCN)]2+ ions.

Barium and sulfate ions form the crumbly barium sulfate precipitate. The final solution looks dense and light-yellow colored.

Potassium ferricyanide with Fe3+ ions forms a red colored complex Fe[Fe(CN)6] solution.

Tannic acid is a big molecule with many OH-groups and it coordinates with Fe3+. The deep -blue colored solution looks like ink.

Tartaric acid coordinates with Fe3+ ions and forms a yellow complex.

HSO3- ions are produced from sodium bisulfite and a red solution of iron(III) hydrogen sulfite solution is formed.

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Published on 01 February 2015

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