2 NaNO₂ (aq) + 2 FeSO₄ (aq) + 2 H₂SO₄ (aq) → Na₂SO₄ (aq) + Fe₂(SO₄)₃ (s) + 2 NO (g) + 2 H₂O (l)

This is an oxidation-reduction (redox) reaction:

NaNO₂ is an oxidizing agent, FeSO₄ is a reducing agent.

This is a precipitation reaction: Fe₂(SO₄)₃ is the formed precipitate.

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

Reactants:

• NaNO₂
  • Names: Sodium nitrite , 7632-00-0 , E250 ... show moreNaNO2 , Nitrous acid, sodium salt show less
  • Appearance: White or slightly yellowish solid ; Hygroscopic white-to-yellow solid in various forms
• FeSO₄ – Iron(II) sulphate
  • Other names: Iron(II) sulfate , Ferrous sulfate , Green vitriol ... show moreIron vitriol , Copperas , Melanterite , Szomolnokite , Ferrous sulfate , Iron sulfate (1:1) , Iron(II) sulfate (1:1) , Ferrous sulfate (anhydrous) , Ferrous sulfate (anh.) , Iron(2+) sulfate (anh.) , FeSO4 , Fe(II)SO4 , Ferrous sulfate anhydrous show less
  • Appearance: White crystals (anhydrous) | White-yellow crystals (monohydrate) | Blue-green crystals (heptahydrate)
• H₂SO₄ – Sulfuric acid
  • Other names: Oil of vitriol , Sulfuric acid, concentrated (> 51% and < 100%) , H2SO4 ... show moreSulphuric acid , Battery acid , Hydrogen sulfate , [SO2(OH)2] , [S(OH)2O2] , Sulfuric acid (aqueous) show less
  • Appearance: Clear, colorless liquid ; Odourless colourless oily hygroscopic liquid ; Colorless to dark-brown, oily, odorless liquid. [Note: Pure compound is a solid below 51°F. Often used in an aqueous solution.]

Products:

• Na₂SO₄
  • Names: Sodium sulfate , Sodium sulphate , Sulfate of sodium ... show moreThenardite (mineral) , Glauber's salt (decahydrate) , Sal mirabilis (decahydrate) , Mirabilite (decahydrate mineral) , Disodium sulfate , Anhydrous sodium sulfate , Sodium sulfate anhydrous , Sodium sulfate, anhydrous , Sodium sulphate anhydrous , Sodium sulphate, anhydrous , Sulfuric acid disodium salt, anhydrous , Disodium sulphate , Salt cake , Na2SO4 , Sulfuric acid disodium salt show less
  • Appearance: White crystalline solid | hygroscopic ; White hygroscopic solid in various forms
• Fe₂(SO₄)₃ – Iron(III) sulfate
  • Other names: Ferric sulfate , Sulfuric acid , Iron(3+) salt (3:2) ... show moreDiiron tris(sulphate) , Iron tersulfate , Iron sesquisulfate , Iron persulfate , Ferric tersulfate , Ferric sesquisulfate , Ferric persulfate , Diiron trisulfate , Iron(III) sulfate(VI) , Ferric sulfate anhydrous show less
  • Appearance: Grayish-white crystals
• NO – Nitrogen monoxide , Oxidonitrogen(•) (additive)
  • Other names: Nitric oxide , Nitrogen(II) oxide , Nitric oxide (radical) ... show moreMononitrogen monoxide , (.)NO , EDRF , Nitrogen monooxide , [NO] , Oxido de nitrogeno(ii) , NO(.) , Oxido nitrico , Stickstoff(ii)-oxid , NO , Oxyde azotique , Oxyde nitrique , Stickstoffmonoxid , Nitrosyl , (NO)(.) , Monoxido de nitrogeno , Endothelium-derived relaxing factor , Nitroxide radical , Nitroxyl , Nitrosyl radical , Hydroxyamine , Nitrogen oxide , Nitrogen protoxide , Nitrosyl hydride , Nitric Oxide show less
  • Appearance: Colourless gas ; Colourless compressed gas ; Colorless gas. [Note: Shipped as a nonliquefied compressed gas.]
• H₂O – Water, oxidane
  • Other names: Water (H2O) , Hydrogen hydroxide (HH or HOH) , Hydrogen oxide ... show moreDihydrogen monoxide (DHMO) (systematic name) , Hydrogen monoxide , Dihydrogen oxide , Hydric acid , Hydrohydroxic acid , Hydroxic acid , Hydrol , Μ-oxido dihydrogen , Κ1-hydroxyl hydrogen(0) show less
  • Appearance: White crystalline solid, almost colorless liquid with a hint of blue, colorless gas