3 Zn (s) + 2 H3PO4 (aq) → 3 H2 (g) + Zn3(PO4)2 (s)

This is an oxidation-reduction (redox) reaction:

3 Zn0 - 6 e- → 3 ZnII (oxidation)

6 HI + 6 e- → 6 H0 (reduction)

Zn is a reducing agent, H3PO4 is an oxidizing agent.

Reactants:

  • Zn
    • Names: Zinc source: wikidata, accessed: 2019-09-07, Zinc powder (pyrophoric) source: ICSC, accessed: 2019-09-04, Zn source: wikidata, accessed: 2019-09-07
    • Appearance: Grey-to-blue powder source: ICSC, accessed: 2019-09-04
  • 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

Products:

  • H2
    • Names: Dihydrogen source: wikidata, accessed: 2019-09-07, Hydrogen source: ICSC, accessed: 2019-09-04source: wikidata, accessed: 2019-09-07, H2 source: wikidata, accessed: 2019-09-07
    • Appearance: Odourless colourless compressed gas source: ICSC, accessed: 2019-09-04
  • Zn3(PO4)2 – Zinc phosphate source: wikipedia, accessed: 2019-09-28source: wikidata, accessed: 2019-09-02
    • Other names: Zinc(II) phosphate source: wikidata, accessed: 2019-09-02
    • Appearance: White solid source: wikipedia, accessed: 2019-09-28