4 K2Cr2O7 (aq) 4 K2CrO4 (aq) + 2 Cr2O3 (s) + 3 O2 (g)

This is an oxidation-reduction (redox) reaction:

4 CrVI + 12 e- 4 CrIII (reduction)

6 O-II - 12 e- 6 O0 (oxidation)

K2Cr2O7 is an oxidizing agent, K2Cr2O7 is a reducing agent.

This is a precipitation reaction: Cr2O3 is the formed precipitate.

This is a gas evolution reaction, O2 is the formed gas.

Reactants:

  • K2Cr2O7Potassium dichromate(VI) source: wikipedia, accessed: 2019-09-27source: wikidata, accessed: 2019-09-02
    • Other names: Potassium dichromate source: wikipedia, accessed: 2019-09-27source: wikidata, accessed: 2019-09-02source: ICSC, accessed: 2019-09-04, Chromium potassium oxide source: wikidata, accessed: 2019-09-02, Dipotassium dichromium heptaoxide source: wikidata, accessed: 2019-09-02
    • Appearance: Red-orange crystalline solid source: wikipedia, accessed: 2019-09-27; Orange-to-red crystals source: ICSC, accessed: 2019-09-04

Products:

  • K2CrO4Potassium chromate source: wikipedia, accessed: 2019-09-27source: wikidata, accessed: 2019-09-02source: ICSC, accessed: 2019-09-04
    • Other names: Chromic acid source: wikipedia, accessed: 2019-09-27, (K2CrO4) source: wikipedia, accessed: 2019-09-27, Dipotassium salt source: wikipedia, accessed: 2019-09-27
    • Appearance: Yellow powder source: wikipedia, accessed: 2019-09-27; Yellow crystals source: ICSC, accessed: 2019-09-04
  • Cr2O3
    • Names: Chromium(III) oxide source: wikipedia, accessed: 2019-09-27, Chromium sesquioxide source: wikipedia, accessed: 2019-09-27source: wikidata, accessed: 2019-09-02, Chromia source: wikipedia, accessed: 2019-09-27source: wikidata, accessed: 2019-09-02
    • Appearance: Light to dark green, fine crystals source: wikipedia, accessed: 2019-09-27; Light-to-dark-green powder source: ICSC, accessed: 2019-09-04
  • O2
    • Names: Dioxygen source: wikidata, accessed: 2019-09-07, Oxygen source: ICSC, accessed: 2019-09-04source: wikidata, accessed: 2019-09-07, Oxygen (liquefied) source: ICSC, accessed: 2019-09-04
    • Appearance: Odourless compressed gas source: ICSC, accessed: 2019-09-04; Liquefied gas. colourless-to-blue extremely cold liquid source: ICSC, accessed: 2019-09-04