Mercury(II) Sulfide Precipitation (Vermilion)

HgCl2 + Na2S → HgS↓ + 2NaCl

概述

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.

参与者

角色 物质 系数 状态
产物 Sodium Chloride NaCl 2 (aq)

日常示例

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

工业重要性

辰砂（HgS）是汞的主要矿石，因其极低的溶度积，硫化汞固化是处置汞废物最稳定的方法之一，被广泛用于汞污染场地的修复稳定化处理。

属性

类型
Precipitation
可逆
否
能量
放热
ΔH
-83.0 kJ/mol

相关反应

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.