6 Cu₂S + 38 HNO₃ → 3 Cu(HSO₄)₂ + 9 Cu(NO₃)₂ + 20 NO + 16 H₂O

This is an oxidation-reduction (redox) reaction:

Cu₂S is a reducing agent, Cu₂S is a reducing agent, HNO₃ is an oxidizing agent.

Reactants:

• Cu₂S – Copper(I) Sulphide
  • Other names: Copper(I) sulfide , Cuprous sulfide , Chalcocite ... show moreCopper glance , Cu2S , Dicopper monosulfide , Dicopper sulphide , Cuprasulfide show less
• 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:

• Cu(HSO₄)₂
• Cu(NO₃)₂ – Copper(II) nitrate
  • Other names: Cupric nitrate , Nitrato de cobre (II) , Нитрат меди (II) (безводный) ... show moreНитрат меди(II) (anh.) , Cu (NO3)2 , Динитрат меди , Азотная кислота, соль меди(2+) , Нитрат меди , Нитрат меди(2+) show less
  • Appearance: Blue crystals | hygroscopic
• 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