Si + 2 NaOH + H2O → Na2SiO3 + 2 H2

This is an oxidation-reduction (redox) reaction:

Si0 - 4 e- → SiIV (oxidation)

4 HI + 4 e- → 4 H0 (reduction)

Reactants:

  • Si
    • Names: Silicon source: wikidata, accessed: 2019-09-07source: ICSC, accessed: 2019-09-04source: NIOSH NPG, accessed: 2019-09-02, Si source: wikidata, accessed: 2019-09-07, Element 14 source: wikidata, accessed: 2019-09-07
    • Appearance: Steel-grey crystals or black-to-brown amorphous powder source: ICSC, accessed: 2019-09-04; Black to gray, lustrous, needle-like crystals. [Note: The amorphous form is a dark-brown powder.] source: NIOSH NPG, accessed: 2019-09-02
  • NaOH
    • Names: Sodium hydroxide source: wikipedia, accessed: 2019-09-27source: wikidata, accessed: 2019-09-02source: ICSC, accessed: 2019-09-04source: NIOSH NPG, accessed: 2019-09-02, Caustic soda source: wikidata, accessed: 2019-09-02source: ICSC, accessed: 2019-09-04source: NIOSH NPG, accessed: 2019-09-02, Lye source: wikidata, accessed: 2019-09-02
    • Appearance: White, waxy, opaque crystals source: wikipedia, accessed: 2019-09-27; White hygroscopic solid in various forms source: ICSC, accessed: 2019-09-04; Colorless to white, odorless solid (flakes, beads, granular form). source: NIOSH NPG, accessed: 2019-09-02
  • H2O – Water, 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:

  • Na2SiO3
    • Names: Sodium metasilicate source: wikidata, accessed: 2019-09-02, Sodium metasilicate (anhydrous) source: ICSC, accessed: 2019-09-04, Sodium sesquisilicate source: wikidata, accessed: 2019-09-02
    • Appearance: Colourless-to-white hygroscopic solid in various forms source: ICSC, accessed: 2019-09-04
  • 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