2 H3PO4 + Ca → 3 H2 + Ca(PO4)2

This is an oxidation-reduction (redox) reaction:

2 PV - 4 e- → 2 PVII (oxidation)

6 HI + 6 e- → 6 H0 (reduction)

Ca0 - 2 e- → CaII (oxidation)

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

Reactants:

  • 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
  • Ca
    • Names: Calcium source: wikidata, accessed: 2019-09-07, Calcium (powder) source: ICSC, accessed: 2019-09-04, Ca source: wikidata, accessed: 2019-09-07
    • Appearance: Silvery-white-to-grey powder source: ICSC, accessed: 2019-09-04

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
  • Ca(PO4)2