4 CuSO4 + 8 KI → 2 Cu2I + 3 I2 + 4 K2SO4

This is an oxidation-reduction (redox) reaction:

4 CuII + 6 e- → 4 Cu1/2 (reduction)

6 I-I - 6 e- → 6 I0 (oxidation)

CuSO4 is an oxidizing agent, KI is a reducing agent.

Reactants:

  • CuSO4 – Copper(II) sulfate source: wikipedia, accessed: 2019-09-27source: wikidata, accessed: 2019-09-02
    • Other names: Cupric sulphate source: wikipedia, accessed: 2019-09-27source: ICSC, accessed: 2019-09-04, Blue vitriol (pentahydrate) source: wikipedia, accessed: 2019-09-27, Bluestone (pentahydrate) source: wikipedia, accessed: 2019-09-27
    • Appearance: Gray-white (anhydrous) | blue (pentahydrate) source: wikipedia, accessed: 2019-09-27; White hygroscopic crystals source: ICSC, accessed: 2019-09-04
  • KI
    • Names: Potassium iodide source: wikidata, accessed: 2019-09-02, KI source: wikidata, accessed: 2019-09-02, Thyrosafe source: wikidata, accessed: 2019-09-02

Products:

  • Cu2I
  • I2
    • Names: Iodine source: ICSC, accessed: 2019-09-04source: NIOSH NPG, accessed: 2019-09-02, Jod source: ICSC, accessed: 2019-09-04, Iode source: ICSC, accessed: 2019-09-04
    • Appearance: Bluish black or dark purple crystals with pungent odour source: ICSC, accessed: 2019-09-04; Violet solid with a sharp, characteristic odor. source: NIOSH NPG, accessed: 2019-09-02
  • K2SO4
    • Names: Potassium sulfate source: wikipedia, accessed: 2019-09-27source: wikidata, accessed: 2019-09-02source: ICSC, accessed: 2019-09-04, Potassium sulphate source: wikipedia, accessed: 2019-09-27source: wikidata, accessed: 2019-09-02, Dipotassium sulfate source: wikidata, accessed: 2019-09-02source: ICSC, accessed: 2019-09-04
    • Appearance: White solid source: wikipedia, accessed: 2019-09-27; Colourless-to-white crystals source: ICSC, accessed: 2019-09-04