CuS + 8 HNO3 → CuNO3 + H2SO4 + 7 NO2 + 3 H2O
This is an oxidation-reduction (redox) reaction:
CuII + e- → CuI (reduction)
S-II - 8 e- → SVI (oxidation)
7 NV + 7 e- → 7 NIV (reduction)
CuS is an oxidizing agent, CuS is a reducing agent, HNO3 is an oxidizing agent.
Reactants:
- CuS – Copper sulfide
- HNO3 – Nitric acid
- Other names: Aqua fortis
, Spirit of niter
, Eau forte
- 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.]
- Other names: Aqua fortis
Products:
- CuNO3
- H2SO4 – Sulfuric acid
- NO2 – Nitrogen dioxide
- Other names: Nitrogen(IV) oxide
, Deutoxide of nitrogen
, Nitrogen peroxide
- 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.]
- Other names: Nitrogen(IV) oxide
- H2O – Water, oxidane