2 KNO3 (aq) → 2 KNO2 (aq) + O2 (g)

This is an oxidation-reduction (redox) reaction:

2 NV + 4 e- → 2 NIII (reduction)

2 O-II - 4 e- → 2 O0 (oxidation)

KNO3 is an oxidizing agent, KNO3 is a reducing agent.

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

Reactants:

  • KNO3 – Potassium nitrate source: wikipedia, accessed: 2019-09-27source: wikidata, accessed: 2019-09-02source: ICSC, accessed: 2019-09-04
    • Other names: Saltpeter source: wikipedia, accessed: 2019-09-27source: wikidata, accessed: 2019-09-02source: ICSC, accessed: 2019-09-04, Saltpetre source: wikipedia, accessed: 2019-09-27source: wikidata, accessed: 2019-09-02, Nitrate of potash source: wikipedia, accessed: 2019-09-27source: wikidata, accessed: 2019-09-02
    • Appearance: White solid source: wikipedia, accessed: 2019-09-27; Colourless-to-white crystalline powder source: ICSC, accessed: 2019-09-04

Products:

  • KNO2
    • Names: Potassium nitrite source: wikipedia, accessed: 2019-09-27source: wikidata, accessed: 2019-09-02source: ICSC, accessed: 2019-09-04, Nitrous acid potassium salt source: ICSC, accessed: 2019-09-04
    • Appearance: White or slight yellow solid | deliquescent source: wikipedia, accessed: 2019-09-27; White-to-yellow deliquescent solid in various forms 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