3 CuS (s) + 14 HNO3 (aq) → 3 Cu(NO3)2 (aq) + 3 H2SO4 (aq) + 8 NO (g) + 4 H2O (l)
This is an oxidation-reduction (redox) reaction:
3 S-II - 24 e- → 3 SVI (oxidation)
8 NV + 24 e- → 8 NII (reduction)
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.]
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