4 HCl (aq) + 2 KI (aq) + 2 NaNO2 (aq) 2 H2O (l) + I2 (s) + 2 NaCl (aq) + 2 KCl (aq) + 2 NO (g)

This is an oxidation-reduction (redox) reaction:

2 I-I - 2 e- 2 I0 (oxidation)

2 NIII + 2 e- 2 NII (reduction)

KI is a reducing agent, NaNO2 is an oxidizing agent.

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

This is a gas evolution reaction, NO is the formed gas.

Reactants:

  • HClChlorane source: wikipedia, accessed: 2019-09-27, Hydrogen chloride source: wikipedia, accessed: 2019-09-27source: wikidata, accessed: 2019-09-02source: ICSC, accessed: 2019-09-04source: NIOSH NPG, accessed: 2019-09-02
    • Other names: Hydrochloric acid source: wikipedia, accessed: 2019-09-27source: NIOSH NPG, accessed: 2019-09-02, Hydrochloric acid gas source: wikipedia, accessed: 2019-09-27, HCl source: wikidata, accessed: 2019-09-02
    • Appearance: Colorless, transparent liquid, fumes in air if concentrated source: wikipedia, accessed: 2019-09-27; Colorless gas source: wikipedia, accessed: 2019-09-27; Colourless compressed liquefied gas with pungent odour source: ICSC, accessed: 2019-09-04; Colorless to slightly yellow gas with a pungent, irritating odor. [Note: Shipped as a liquefied compressed gas.] 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
  • NaNO2
    • Names: Sodium nitrite source: wikipedia, accessed: 2019-09-27source: wikidata, accessed: 2019-09-02source: ICSC, accessed: 2019-09-04, 7632-00-0 source: wikidata, accessed: 2019-09-02, E250 source: wikidata, accessed: 2019-09-02
    • Appearance: White or slightly yellowish solid source: wikipedia, accessed: 2019-09-27; Hygroscopic white-to-yellow solid in various forms source: ICSC, accessed: 2019-09-04

Products:

  • H2OWater, 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
  • 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
  • NaClSodium chloride source: wikipedia, accessed: 2019-09-27source: wikidata, accessed: 2019-09-02
    • Other names: Salt source: wikidata, accessed: 2019-09-02, Table salt source: wikidata, accessed: 2019-09-02, Common salt source: wikidata, accessed: 2019-09-02
    • Appearance: Colorless cubic crystals source: wikipedia, accessed: 2019-09-27
  • KCl
    • Names: Potassium chloride source: wikipedia, accessed: 2019-09-27source: wikidata, accessed: 2019-09-02source: ICSC, accessed: 2019-09-04, Sylvite source: wikipedia, accessed: 2019-09-27source: wikidata, accessed: 2019-09-02, Muriate of potash source: wikipedia, accessed: 2019-09-27source: wikidata, accessed: 2019-09-02
    • Appearance: White crystalline solid source: wikipedia, accessed: 2019-09-27; Colourless hygroscopic crystals source: ICSC, accessed: 2019-09-04
  • NONitrogen monoxide source: wikipedia, accessed: 2019-09-27source: wikidata, accessed: 2019-09-02source: NIOSH NPG, accessed: 2019-09-02, Oxidonitrogen(•) (additive) source: wikipedia, accessed: 2019-09-27
    • Other names: Nitric oxide source: wikipedia, accessed: 2019-09-27source: ICSC, accessed: 2019-09-04source: NIOSH NPG, accessed: 2019-09-02source: wikidata, accessed: 2019-09-02, Nitrogen(II) oxide source: wikipedia, accessed: 2019-09-27, Nitric oxide (radical) source: wikidata, accessed: 2019-09-02
    • Appearance: Colourless gas source: wikipedia, accessed: 2019-09-27; Colourless compressed gas source: ICSC, accessed: 2019-09-04; Colorless gas. [Note: Shipped as a nonliquefied compressed gas.] source: NIOSH NPG, accessed: 2019-09-02