Chromium(III) Hydroxide Precipitation

CrCl3 + 3NaOH → Cr(OH)3↓ + 3NaCl

Обзор

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]⁻.

Участники

Роль Вещество Коэффициент Состояние
Реагент Sodium Hydroxide NaOH 3 (aq)
Продукт Sodium Chloride NaCl 3 (aq)

Пример из жизни

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

Промышленное значение

Chromium(III) hydroxide precipitation is used in chromium removal from industrial wastewater, particularly from chrome plating and leather tanning effluents.

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.