Mercury(II) Sulfide Precipitation (Vermilion)

HgCl2 + Na2S → HgS↓ + 2NaCl

Ikhtisar

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.

Peserta

Peran Zat Koefisien Keadaan
Produk Sodium Chloride NaCl 2 (aq)

Contoh Sehari-hari

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

Pentingnya dalam Industri

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

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.