3 HgS + 4 HNO3 + 12 HCl → 3 HgCl4 + 3 S + 4 NO + 8 H2O
This is an oxidation-reduction (redox) reaction:
3 S-II - 6 e- → 3 S0 (oxidation)
4 NV + 12 e- → 4 NII (reduction)
3 HgII - 6 e- → 3 HgIV (oxidation)
HgS is a reducing agent, HNO3 is an oxidizing agent, HgS is a reducing agent.
Reactants:
- HgS – Mercury 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.]
- HCl – Chlorane , Hydrogen chloride
- Other names: Hydrochloric acid , M , Uriatic acid
- Appearance: Colorless, transparent liquid, fumes in air if concentrated ; Colorless gas ; Colourless compressed liquefied gas with pungent odour ; Colorless to slightly yellow gas with a pungent, irritating odor. [Note: Shipped as a liquefied compressed gas.]
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