10 Cr (s) + 6 HNO3 (aq) → 3 N2 (g) + 5 Cr2O3 (s) + 3 H2O (l)

This is an oxidation-reduction (redox) reaction:

6 NV + 30 e- → 6 N0 (reduction)

10 Cr0 - 30 e- → 10 CrIII (oxidation)

HNO3 is an oxidizing agent, Cr is a reducing 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
  • HNO3 – Nitric acid source: wikipedia, accessed: 2019-09-27source: wikidata, accessed: 2019-09-02source: NIOSH NPG, accessed: 2019-09-02
    • Other names: Aqua fortis source: wikipedia, accessed: 2019-09-27source: wikidata, accessed: 2019-09-02source: NIOSH NPG, accessed: 2019-09-02, Spirit of niter source: wikipedia, accessed: 2019-09-27source: wikidata, accessed: 2019-09-02, Eau forte source: wikipedia, accessed: 2019-09-27
    • Appearance: Colorless, yellow or red fuming liquid source: wikipedia, accessed: 2019-09-27; Colourless-to-yellow liquid with pungent odour source: ICSC, accessed: 2019-09-04; Colorless, yellow, or red, fuming liquid with an acrid, suffocating odor. [Note: Often used in an aqueous solution. Fuming nitric acid is concentrated nitric acid that contains dissolved nitrogen dioxide.] source: NIOSH NPG, accessed: 2019-09-02

Products:

  • N2
    • Names: Dinitrogen source: wikidata, accessed: 2019-09-07, Nitrogen (compressed gas) source: ICSC, accessed: 2019-09-04, Nitrogen (liquified) source: ICSC, accessed: 2019-09-04
    • Appearance: Odourless colourless compressed gas source: ICSC, accessed: 2019-09-04; Odourless colourless extremely cold liquid 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
  • 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