Chromate-Dichromate Equilibrium
2CrO42− + 2H+ ⇌ Cr2O72− + H2O
نظرة عامة
Chromate (yellow, CrO₄²⁻) converts to dichromate (orange, Cr₂O₇²⁻) in acidic solution and vice versa in basic solution. This pH-dependent equilibrium involves condensation of two tetrahedral chromate units. While chromium remains at +6 throughout, this equilibrium is fundamental to Cr(VI) redox chemistry.
المشاركون
| الدور | المادة | المعامل | الحالة |
|---|---|---|---|
| منتج | Water H₂O | 1 | (l) |
مثال من الحياة اليومية
Adding acid to yellow potassium chromate solution turns it orange, and adding base reverses it, demonstrating Le Chatelier's principle.
الأهمية الصناعية
Chromate/dichromate equilibrium is important in chrome plating, leather tanning, and in understanding Cr(VI) environmental contamination.
الخصائص
- النوع
- Redox
- قابل للعكس
- نعم
- الطاقة
- طارد للحرارة
- ΔH
- -14,0 kJ/mol
التفاعلات ذات الصلة
Iron(II) to Iron(III) Oxidation by Oxygen
Bleaching with Sodium Hypochlorite
Copper Reduction of Silver Ion
Aqua Regia Dissolving Gold
Cerium(IV) Reduction by Iron(II)
Copper Oxidation by Nitric Acid
Hypochlorite Oxidation of Hydrogen Peroxide
Hydrogen Peroxide as Oxidizing Agent (Acidic)
Hydrogen Peroxide Disproportionation
Displacement of Hydrogen from Acid by Magnesium
Frequently Asked Questions
What is the equation for Chromate-Dichromate Equilibrium?
The balanced equation is: 2CrO₄²⁻ + 2H⁺ ⇌ Cr₂O₇²⁻ + H₂O.
What type of reaction is Chromate-Dichromate Equilibrium?
Chromate-Dichromate Equilibrium is a redox reaction. It is reversible under certain conditions.
Is Chromate-Dichromate Equilibrium exothermic or endothermic?
Chromate-Dichromate Equilibrium is exothermic (releases energy). The enthalpy change (ΔH) is -14.0 kJ/mol.