“Bleeding iron” experiment
How to make iron bleed in a solution
Iron is often associated with strength and invulnerability: Iron Man, an iron grip, an iron will. But does iron have a weak spot? In this experiment you’ll see how iron bleeds without a single wound!
Wear protective gloves, a mask and glasses and work in a well-ventilated room. Observe safety rules when working with concentrated acids.
Warning! Do not try this at home. Only under professional supervision.
Reagents and equipment:
- concentrated hydrochloric acid;
- 3% hydrogen peroxide solution;
- 10 g of ammonium thiocyanate;
- iron clip or wire;
In the hydrogen peroxide solution dissolve ammonium thiocyanate and add a few drops of concentrated hydrochloric acid. Then lower the iron clip into the resulting mixture.
Iron dissolves in hydrochloric acid with the formation of iron(II) chloride. Then, the iron(II) ion that forms is oxidized by hydrogen peroxide to iron(III), which reacts with the thiocyanate ion, forming a red compound of a transitional composition – iron(III) thiocyanate.
Fe + 2HCl → FeCl₂ + H₂
Fe²⁺ + H₂O₂ + 2H⁺→ Fe³⁺ + 2H₂O
Fe³⁺ + nCNS⁻ → [Fe(H₂O)ₙ(CNS)₆₋ₙ]ⁿ⁻³