5 KNO3 + 2 P → P2O5 + 5 KNO2

This is an oxidation-reduction (redox) reaction:

2 P0 - 10 e- → 2 PV (oxidation)

5 NV + 10 e- → 5 NIII (reduction)

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

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
  • P

    Products:

    • P2O5
      • Names: Phosphorus pentoxide source: wikipedia, accessed: 2019-09-27source: ICSC, accessed: 2019-09-04, Diphosphorus pentoxide source: wikipedia, accessed: 2019-09-27source: ICSC, accessed: 2019-09-04, Phosphorus(V) oxide source: wikipedia, accessed: 2019-09-27
      • Appearance: White powder | very deliquescent | odorless source: wikipedia, accessed: 2019-09-27; Hygroscopic white crystals or powder source: ICSC, accessed: 2019-09-04
    • 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