6 NaBr + Na2Cr2O7 + 7 H2SO4 3 Br2 + Cr2(SO4)3 + 4 Na2(SO4) + 7 H2O

This is an oxidation-reduction (redox) reaction:

6 Br-I - 6 e- 6 Br0 (oxidation)

2 CrVI + 6 e- 2 CrIII (reduction)

NaBr is a reducing agent, Na2Cr2O7 is an oxidizing agent.

Reactants:

  • NaBrSodium bromide source: wikipedia, accessed: 2019-09-27source: wikidata, accessed: 2019-09-02
    • Other names: Bromide salt of sodium source: wikidata, accessed: 2019-09-02, Trisodium tribromide source: wikidata, accessed: 2019-09-02, NaBr source: wikidata, accessed: 2019-09-02
    • Appearance: White powder, hygroscopic source: wikipedia, accessed: 2019-09-27
  • Na2Cr2O7Sodium dichromate source: wikipedia, accessed: 2019-09-27source: wikidata, accessed: 2019-09-02
    • Other names: Chromic acid disodium salt source: wikipedia, accessed: 2019-09-27, Sodium dichromate (anhydrous) source: ICSC, accessed: 2019-09-04, Disodium salt source: wikidata, accessed: 2019-09-02
    • Appearance: Bright orange source: wikipedia, accessed: 2019-09-27; Red-to-orange hygroscopic crystals source: ICSC, accessed: 2019-09-04
  • H2SO4Sulfuric 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:

  • 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
  • Cr2(SO4)3Chromium(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
  • Na2(SO4)
  • H2OWater, 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