H2O2 (aq) + 2 KI (aq) I2 (s) + 2 KOH (aq)

This is an oxidation-reduction (redox) reaction:

2 I-I - 2 e- 2 I0 (oxidation)

2 O-I + 2 e- 2 O-II (reduction)

KI is a reducing agent, H2O2 is an oxidizing agent.

This is a precipitation reaction: I2 is the formed precipitate.

Reactants:

  • H2O2Hydrogen peroxide source: wikipedia, accessed: 2019-09-27source: wikidata, accessed: 2019-09-02source: NIOSH NPG, accessed: 2019-09-02
    • Other names: Dioxidane source: wikipedia, accessed: 2019-09-27source: wikidata, accessed: 2019-09-02, Oxidanyl source: wikipedia, accessed: 2019-09-27, Perhydroxic acid source: wikipedia, accessed: 2019-09-27
    • Appearance: Very light blue color; colorless in solution source: wikipedia, accessed: 2019-09-27; Colourless liquid source: ICSC, accessed: 2019-09-04; Colorless liquid with a slightly sharp odor. [Note: The pure compound is a crystalline solid below 12°F. Often used in an aqueous solution.] source: NIOSH NPG, accessed: 2019-09-02
  • 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:

  • 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
  • KOHPotassium hydroxide source: wikipedia, accessed: 2019-09-27source: wikidata, accessed: 2019-09-02source: ICSC, accessed: 2019-09-04source: NIOSH NPG, accessed: 2019-09-02
    • Other names: Caustic potash source: wikipedia, accessed: 2019-09-27source: wikidata, accessed: 2019-09-02source: ICSC, accessed: 2019-09-04source: NIOSH NPG, accessed: 2019-09-02, Lye source: wikipedia, accessed: 2019-09-27source: wikidata, accessed: 2019-09-02, Potash lye source: wikipedia, accessed: 2019-09-27source: wikidata, accessed: 2019-09-02
    • Appearance: White solid, deliquescent source: wikipedia, accessed: 2019-09-27; White hygroscopic solid in various forms source: ICSC, accessed: 2019-09-04; Odorless, white or slightly yellow lumps, rods, flakes, sticks, or pellets. [Note: May be used as an aqueous solution.] source: NIOSH NPG, accessed: 2019-09-02