FeS + 10 HNO3 → Fe(NO3)3 + SO2 + 7 NO2 + 5 H2O

This is an oxidation-reduction (redox) reaction:

S-II-6e-→SIV(oxidation)

7NV+7e-→7NIV(reduction)

FeII-1e-→FeIII(oxidation)

FeS is a reducing agent, HNO3 is an oxidizing agent, FeS is a reducing agent.

Reactants:

• FeS
  • Names: Iron(II) sulfide , Iron sulfide , Ferrous sulfide ... show moreBlack iron sulfide , Protosulphuret of iron , Ferrous sulphide , Iron(II) sulphide show less
  • Appearance: Gray, sometimes in lumps or powder
• HNO3 – Nitric acid
  • Other names: Aqua fortis , Spirit of niter , Eau forte ... show moreHydrogen nitrate , Acidum nitricum , Nitric acid (> 70% in water) , Fuming nitric acid , Engravers acid , HONO2 , Red fuming nitric acid , RFNA , White fuming nitric acid (WFNA) show less
  • Appearance: Colorless, yellow or red fuming liquid ; Colourless-to-yellow liquid with pungent odour ; Colorless, yellow, or red, fuming liquid with an acrid, suffocating odor. [Note: Often used in an aqueous solution. Fuming nitric acid is concentrated nitric acid that contains dissolved nitrogen dioxide.]

Products:

• Fe(NO3)3 – Iron(III) nitrate
  • Other names: Ferric nitrate , Nitric acid , Iron(3+) salt , Iron (III) nitrate
  • Appearance: Pale violet crystals | hygroscopic
• SO2 – Sulfur dioxide
  • Other names: Sulfurous anhydride , Sulphur dioxide , Sulfurous acid anhydride ... show moreSulfurous oxide , Sulfur oxide , Sulphur dioxide , sulfur dioxide , SO2 , R-764 show less
  • Appearance: Colorless gas ; Colourless gas or compressed liquefied gas with pungent odour ; Colorless gas with a characteristic, irritating, pungent odor. [Note: A liquid below 14°F. Shipped as a liquefied compressed gas.]
• NO2 – Nitrogen dioxide
  • Other names: Nitrogen(IV) oxide , Deutoxide of nitrogen , Nitrogen peroxide ... show moreNO2 , NO2(.) , Dinitrogen tetroxide (see notes) , Nitrogen tetroxide , Dinitrogen tetroxide show less
  • Appearance: Brown gas ; Reddish-brown gas or brown or yellow liquid with pungent odour ; Yellowish-brown liquid or reddish-brown gas (above 70°F) with a pungent, acrid odor. [Note: In solid form (below 15°F) it is found structurally as N2O4.]
• 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