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.
- HCl – Chlorane , Hydrogen chloride
- Other names: Hydrochloric acid , Hydrochloric acid gas , HCl
- Appearance: Colorless, transparent liquid, fumes in air if concentrated ; Colorless gas ; Colourless compressed liquefied gas with pungent odour ; Colorless to slightly yellow gas with a pungent, irritating odor. [Note: Shipped as a liquefied compressed gas.]
- H2O – Water, oxidane
- NaCl – Sodium chloride
- NO – Nitrogen monoxide , Oxidonitrogen(•) (additive)