Br2 (aq) + 2 K4[Fe(CN)6] (aq) → 2 KBr (aq) + 2 K3[Fe(CN)6] (aq)

This is an oxidation-reduction (redox) reaction:

2 Br0 + 2 e- → 2 Br-I (reduction)

2 FeII - 2 e- → 2 FeIII (oxidation)

Br2 is an oxidizing agent, K4[Fe(CN)6] is a reducing agent.

Reactants:

  • Br2
    • Names: Bromine source: ICSC, accessed: 2019-09-04source: NIOSH NPG, accessed: 2019-09-02, Molecular bromine source: NIOSH NPG, accessed: 2019-09-02
    • Appearance: Fuming red-to-brown liquid with pungent odour source: ICSC, accessed: 2019-09-04; Dark reddish-brown, fuming liquid with suffocating, irritating fumes. source: NIOSH NPG, accessed: 2019-09-02
  • K4[Fe(CN)6] – Potassium hexacyanidoferrate(II) source: wikipedia, accessed: 2019-09-27
    • Other names: Potassium ferrocyanide source: wikipedia, accessed: 2019-09-27source: wikidata, accessed: 2019-09-02, (Yellow) Prussiate of Potash source: wikipedia, accessed: 2019-09-27, Potassium hexacyanoferrate (II) trihydrate source: wikipedia, accessed: 2019-09-27
    • Appearance: Light yellow, crystalline granules source: wikipedia, accessed: 2019-09-27

Products:

  • KBr
    • Names: Potassium bromide source: wikipedia, accessed: 2019-09-27source: wikidata, accessed: 2019-09-02, KBr source: wikidata, accessed: 2019-09-02, Kaliumbromid source: wikidata, accessed: 2019-09-02
    • Appearance: White solid source: wikipedia, accessed: 2019-09-27
  • K3[Fe(CN)6] – Potassium hexacyanoferrate(III) source: wikipedia, accessed: 2019-09-27
    • Other names: Potassium ferricyanide source: wikipedia, accessed: 2019-09-27source: wikidata, accessed: 2019-09-02source: ICSC, accessed: 2019-09-04, Red prussiate of Potash source: wikipedia, accessed: 2019-09-27, Prussian red source: wikipedia, accessed: 2019-09-27
    • Appearance: Deep red crystals, sometimes small pellets, orange to dark red powder source: wikipedia, accessed: 2019-09-27; Red crystalline powder source: ICSC, accessed: 2019-09-04