Cr (s) + 2 NaOH (aq) + 3 H2O2 (aq) Na2CrO4 (aq) + 4 H2O (l)

This is an oxidation-reduction (redox) reaction:

Cr0 - 6 e- CrVI (oxidation)

6 O-I + 6 e- 6 O-II (reduction)

Cr is a reducing agent, H2O2 is an oxidizing agent.

Reactants:

  • Cr
    • Names: Chromium source: wikidata, accessed: 2019-09-07source: ICSC, accessed: 2019-09-04source: NIOSH NPG, accessed: 2019-09-02, Chromium metal source: NIOSH NPG, accessed: 2019-09-02, Cr source: wikidata, accessed: 2019-09-07
    • Appearance: Grey powder source: ICSC, accessed: 2019-09-04; Blue-white to steel-gray, lustrous, brittle, hard, odorless solid. source: NIOSH NPG, accessed: 2019-09-02
  • NaOH
    • Names: Sodium hydroxide source: wikipedia, accessed: 2019-09-27source: wikidata, accessed: 2019-09-02source: ICSC, accessed: 2019-09-04source: NIOSH NPG, accessed: 2019-09-02, Caustic soda source: wikidata, accessed: 2019-09-02source: ICSC, accessed: 2019-09-04source: NIOSH NPG, accessed: 2019-09-02, Lye source: wikidata, accessed: 2019-09-02
    • Appearance: White, waxy, opaque crystals source: wikipedia, accessed: 2019-09-27; White hygroscopic solid in various forms source: ICSC, accessed: 2019-09-04; Colorless to white, odorless solid (flakes, beads, granular form). source: NIOSH NPG, accessed: 2019-09-02
  • H2O2Hydrogen peroxide source: wikipedia, accessed: 2019-09-27source: wikidata, accessed: 2019-09-02source: NIOSH NPG, accessed: 2019-09-02
    • Other names: Dioxidane source: wikipedia, accessed: 2019-09-27source: wikidata, accessed: 2019-09-02, Oxidanyl source: wikipedia, accessed: 2019-09-27, Perhydroxic acid source: wikipedia, accessed: 2019-09-27
    • Appearance: Very light blue color; colorless in solution source: wikipedia, accessed: 2019-09-27; Colourless liquid source: ICSC, accessed: 2019-09-04; Colorless liquid with a slightly sharp odor. [Note: The pure compound is a crystalline solid below 12°F. Often used in an aqueous solution.] source: NIOSH NPG, accessed: 2019-09-02

Products:

  • Na2CrO4Sodium 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, (Na2CrO4) source: wikipedia, accessed: 2019-09-27, Disodium salt source: wikipedia, accessed: 2019-09-27
    • Appearance: Yellow crystals source: wikipedia, accessed: 2019-09-27; Yellow hygroscopic crystals source: ICSC, accessed: 2019-09-04
  • 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