Chromium(III) Hydroxide Precipitation

CrCl3 + 3NaOH → Cr(OH)3↓ + 3NaCl

概要

Chromium(III) chloride reacts with sodium hydroxide to form a green gelatinous precipitate of chromium(III) hydroxide (Ksp = 6.3 × 10⁻³¹). Cr(OH)₃ is amphoteric, dissolving in both excess acid and excess NaOH. In excess NaOH, it forms the green chromite ion [Cr(OH)₄]⁻.

参加者

役割 物質 係数 状態
反応物 Sodium Hydroxide NaOH 3 (aq)
生成物 Sodium Chloride NaCl 3 (aq)

日常の例

The green color of some gemstones like emerald is due to chromium(III) ions, the same oxidation state that produces this green precipitate.

産業上の重要性

水酸化クロム(III)沈殿は、特にクロムメッキや皮革なめしの排水から、工業排水中のクロムを除去するために使用されています。

特性

タイプ
Precipitation
可逆的
いいえ
エネルギー
発熱性
ΔH
-90.0 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) Lead Carbonate Precipitation Lead Chloride Precipitation Calcium Carbonate Precipitation Iron(III) Hydroxide Precipitation

Frequently Asked Questions

What is the equation for Chromium(III) Hydroxide Precipitation?
The balanced equation is: CrCl₃ + 3NaOH → Cr(OH)₃↓ + 3NaCl.
What type of reaction is Chromium(III) Hydroxide Precipitation?
Chromium(III) Hydroxide Precipitation is a precipitation reaction.
Is Chromium(III) Hydroxide Precipitation exothermic or endothermic?
Chromium(III) Hydroxide Precipitation is exothermic (releases energy). The enthalpy change (ΔH) is -90.0 kJ/mol.