Mercury(II) Sulfide Precipitation (Vermilion)

HgCl2 + Na2S → HgS↓ + 2NaCl

Übersicht

Mercury(II) chloride reacts with sodium sulfide to form a black precipitate of mercury(II) sulfide (Ksp = 2 × 10⁻⁵²), the most insoluble compound commonly encountered. The black form (metacinnabar) slowly converts to the red form (cinnabar/vermilion) upon heating. HgS is so insoluble it is considered environmentally immobile.

Teilnehmer

Rolle Substanz Koeffizient Zustand
Produkt Sodium Chloride NaCl 2 (aq)

Alltägliches Beispiel

Vermilion pigment, prized since antiquity for its brilliant red color in Chinese lacquerware and Renaissance paintings, is red mercury sulfide.

Industrielle Bedeutung

Mercury sulfide as cinnabar is the primary mercury ore. HgS immobilization is used in mercury waste stabilization because of its extreme insolubility.

Eigenschaften

Typ
Precipitation
Reversibel
Nein
Energie
Exotherm
ΔH
-83,0 kJ/mol

Verwandte Reaktionen

Aluminum Hydroxide Precipitation Barium Carbonate Precipitation Barium Sulfate Precipitation Cadmium Sulfide Precipitation (Yellow) Calcium Fluoride Precipitation (Fluorite) Calcium Phosphate Precipitation (Bone Mineral) Chromium(III) Hydroxide Precipitation Lead Carbonate Precipitation Lead Chloride Precipitation Iron(III) Hydroxide Precipitation

Frequently Asked Questions

What is the equation for Mercury(II) Sulfide Precipitation (Vermilion)?
The balanced equation is: HgCl₂ + Na₂S → HgS↓ + 2NaCl.
What type of reaction is Mercury(II) Sulfide Precipitation (Vermilion)?
Mercury(II) Sulfide Precipitation (Vermilion) is a precipitation reaction.
Is Mercury(II) Sulfide Precipitation (Vermilion) exothermic or endothermic?
Mercury(II) Sulfide Precipitation (Vermilion) is exothermic (releases energy). The enthalpy change (ΔH) is -83.0 kJ/mol.