H3PO2 + 4 AgNO3 + 2 H2O H3PO4 + 4 Ag + 4 HNO3

This is an oxidation-reduction (redox) reaction:

PI - 4 e- PV (oxidation)

4 AgI + 4 e- 4 Ag0 (reduction)

H3PO2 is a reducing agent, AgNO3 is an oxidizing agent.

Reactants:

  • H3PO2Phosphinic acid source: wikipedia, accessed: 2019-09-27source: wikidata, accessed: 2019-09-02
    • Other names: Hypophosphorous acid source: wikipedia, accessed: 2019-09-27source: wikidata, accessed: 2019-09-02, Hydroxy(oxo)-λ5-phosphane source: wikipedia, accessed: 2019-09-27
    • Appearance: Colorless, deliquescent crystals or oily liquid source: wikipedia, accessed: 2019-09-27
  • AgNO3Silver(I) nitrate, Silver nitrate source: wikipedia, accessed: 2019-09-28
    • Other names: Silver nitrate source: wikipedia, accessed: 2019-09-28source: wikidata, accessed: 2019-09-02source: ICSC, accessed: 2019-09-04, Nitric acid silver(1+) salt source: wikipedia, accessed: 2019-09-28, Lapis infernalis source: wikipedia, accessed: 2019-09-28
    • Appearance: Colorless solid source: wikipedia, accessed: 2019-09-28; Odourless colourless or white 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

Products:

  • H3PO4
    • Names: Phosphoric acid source: wikipedia, accessed: 2019-09-27source: wikidata, accessed: 2019-09-02source: ICSC, accessed: 2019-09-04source: NIOSH NPG, accessed: 2019-09-02, Orthophosphoric acid source: wikidata, accessed: 2019-09-02source: ICSC, accessed: 2019-09-04source: NIOSH NPG, accessed: 2019-09-02, Phosphoric(V) acid source: wikidata, accessed: 2019-09-02
    • Appearance: Hygroscopic colourless crystals source: ICSC, accessed: 2019-09-04; Thick, colorless, odorless, crystalline solid. [Note: Often used in an aqueous solution.] source: NIOSH NPG, accessed: 2019-09-02
  • Ag
    • Names: Silver source: wikidata, accessed: 2019-09-07source: ICSC, accessed: 2019-09-04, Ag source: wikidata, accessed: 2019-09-07, Element 47 source: wikidata, accessed: 2019-09-07
    • Appearance: White metal. turns dark on exposure to ozone, hydrogen sulfide or sulfur source: ICSC, accessed: 2019-09-04
  • HNO3Nitric 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