3 CuS + 4 HNO3 → 3 Cu(NO3) + 3 S + NO + 2 H2O
This is an oxidation-reduction (redox) reaction:
3 CuII + 3 e- → 3 CuI (reduction)
3 S-II - 6 e- → 3 S0 (oxidation)
NV + 3 e- → NII (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.]
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