3 H2O + Se + 2 (Cd)2+ → 2 Cd + SeO32- + 6 H+

This is an oxidation-reduction (redox) reaction:

2 CdII + 4 e- → 2 Cd0 (reduction)

Se0 - 4 e- → SeIV (oxidation)

Cd2+ is an oxidizing agent, Se is a reducing agent.

Reactants:

  • 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
  • Se
    • Names: Selenium source: wikidata, accessed: 2019-09-07source: ICSC, accessed: 2019-09-04source: NIOSH NPG, accessed: 2019-09-02, Se source: wikidata, accessed: 2019-09-07, Selen source: wikidata, accessed: 2019-09-07
    • Appearance: Grey solid in various forms source: ICSC, accessed: 2019-09-04; Amorphous or crystalline, red to gray solid. [Note: Occurs as an impurity in most sulfide ores.] source: NIOSH NPG, accessed: 2019-09-02
  • Cd2+

Products:

  • Cd
    • Names: Cadmium source: wikidata, accessed: 2019-09-07source: ICSC, accessed: 2019-09-04, Cd source: wikidata, accessed: 2019-09-07, Element 48 source: wikidata, accessed: 2019-09-07, 48 source: wikidata, accessed: 2019-09-07
    • Appearance: Soft blue-white metal lumps or grey powder. malleable. turns brittle on exposure to 80°c. tarnishes on exposure to moist air source: ICSC, accessed: 2019-09-04
  • SeO32-
  • H+