Mercury(II) Sulfide Precipitation (Vermilion)

HgCl2 + Na2S → HgS↓ + 2NaCl

概要

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.

参加者

役割 物質 係数 状態
生成物 Sodium Chloride NaCl 2 (aq)

日常の例

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

産業上の重要性

辰砂（HgS）は水銀の主要鉱石である。HgSの固定化は水銀廃棄物処理と重汚染土壌浄化において利用される。バーミリオン顔料は美術・伝統工芸での歴史的利用で知られる。

特性

タイプ
Precipitation
可逆的
いいえ
エネルギー
発熱性
ΔH
-83.0 kJ/mol

関連する反応

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.