4 HNO2 + S H2 + 4 NO + H2SO4

This is an oxidation-reduction (redox) reaction:

S0 - 6 e- SVI (oxidation)

2 HI + 2 e- 2 H0 (reduction)

4 NIII + 4 e- 4 NII (reduction)

S is a reducing agent, HNO2 is an oxidizing agent, HNO2 is an oxidizing agent.

Reactants:

  • HNO2Nitrous acid source: wikipedia, accessed: 2019-09-27source: wikidata, accessed: 2019-09-02, Hydroxidooxidonitrogen source: wikipedia, accessed: 2019-09-27source: wikidata, accessed: 2019-09-02
    • Other names: HNO2 source: wikidata, accessed: 2019-09-02, [NO(OH)] source: wikidata, accessed: 2019-09-02, Nitrosyl hydroxide source: wikidata, accessed: 2019-09-02, Dioxonitric acid source: wikidata, accessed: 2019-09-02
    • Appearance: Pale blue solution source: wikipedia, accessed: 2019-09-27
  • S
    • Names: Sulfur source: wikidata, accessed: 2019-09-07source: ICSC, accessed: 2019-09-04, S source: wikidata, accessed: 2019-09-07, Sulphur source: wikidata, accessed: 2019-09-07source: ICSC, accessed: 2019-09-04
    • Appearance: Yellow solid in various forms source: ICSC, accessed: 2019-09-04

Products:

  • H2
    • Names: Dihydrogen source: wikidata, accessed: 2019-09-07, Hydrogen source: ICSC, accessed: 2019-09-04source: wikidata, accessed: 2019-09-07, H2 source: wikidata, accessed: 2019-09-07
    • Appearance: Odourless colourless compressed gas 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
  • H2SO4Sulfuric acid source: wikipedia, accessed: 2019-09-27source: wikidata, accessed: 2019-09-07source: NIOSH NPG, accessed: 2019-09-02
    • Other names: Oil of vitriol source: wikipedia, accessed: 2019-09-27source: wikidata, accessed: 2019-09-07source: ICSC, accessed: 2019-09-04source: NIOSH NPG, accessed: 2019-09-02, Sulfuric acid, concentrated (> 51% and < 100%) source: ICSC, accessed: 2019-09-04, H2SO4 source: wikidata, accessed: 2019-09-07
    • Appearance: Clear, colorless liquid source: wikipedia, accessed: 2019-09-27; Odourless colourless oily hygroscopic liquid source: ICSC, accessed: 2019-09-04; Colorless to dark-brown, oily, odorless liquid. [Note: Pure compound is a solid below 51°F. Often used in an aqueous solution.] source: NIOSH NPG, accessed: 2019-09-02