2 KCr2O7 + 14 KBr + 14 H2SO4 → 2 Cr2(SO4)3 + 8 K2SO4 + 14 H2O + 7 Br2

This is an oxidation-reduction (redox) reaction:

14 Br-I - 14 e- → 14 Br0 (oxidation)

4 Cr13/2 + 14 e- → 4 CrIII (reduction)

KBr is a reducing agent, KCr2O7 is an oxidizing agent.

Reactants:

  • KCr2O7
  • 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
  • H2SO4 – Sulfuric acid source: wikipedia, accessed: 2019-09-27source: wikidata, accessed: 2019-09-07source: NIOSH NPG, accessed: 2019-09-02
    • Other names: Oil of vitriol source: wikipedia, accessed: 2019-09-27source: wikidata, accessed: 2019-09-07source: ICSC, accessed: 2019-09-04source: NIOSH NPG, accessed: 2019-09-02, Sulfuric acid, concentrated (> 51% and < 100%) source: ICSC, accessed: 2019-09-04, H2SO4 source: wikidata, accessed: 2019-09-07
    • Appearance: Clear, colorless liquid source: wikipedia, accessed: 2019-09-27; Odourless colourless oily hygroscopic liquid source: ICSC, accessed: 2019-09-04; Colorless to dark-brown, oily, odorless liquid. [Note: Pure compound is a solid below 51°F. Often used in an aqueous solution.] source: NIOSH NPG, accessed: 2019-09-02

Products:

  • Cr2(SO4)3 – Chromium(III) sulfate source: wikipedia, accessed: 2019-09-27source: wikidata, accessed: 2019-09-02
    • Other names: Basic chromium sulfate source: wikipedia, accessed: 2019-09-27, Chromic sulfate source: wikipedia, accessed: 2019-09-27
    • Appearance: Reddish-brown crystals (anhydrous), purple crystals (hydrated) source: wikipedia, accessed: 2019-09-27
  • K2SO4
    • Names: Potassium sulfate source: wikipedia, accessed: 2019-09-27source: wikidata, accessed: 2019-09-02source: ICSC, accessed: 2019-09-04, Potassium sulphate source: wikipedia, accessed: 2019-09-27source: wikidata, accessed: 2019-09-02, Dipotassium sulfate source: wikidata, accessed: 2019-09-02source: ICSC, accessed: 2019-09-04
    • Appearance: White solid source: wikipedia, accessed: 2019-09-27; Colourless-to-white crystals source: ICSC, accessed: 2019-09-04
  • H2O – Water, oxidane source: wikipedia, accessed: 2019-09-27
    • Other names: Water (H2O) source: wikipedia, accessed: 2019-09-27, Hydrogen hydroxide (HH or HOH) source: wikipedia, accessed: 2019-09-27, Hydrogen oxide source: wikipedia, accessed: 2019-09-27
    • Appearance: White crystalline solid, almost colorless liquid with a hint of blue, colorless gas source: wikipedia, accessed: 2019-09-27
  • 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