Chromate-Dichromate Equilibrium

2CrO₄²⁻ + 2H⁺ ⇌ Cr₂O₇²⁻ + H₂O

Descripción general

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.

Participantes

Rol	Sustancia	Coeficiente	Estado
Producto	Water H₂O	1	(l)

Ejemplo cotidiano

Adding acid to yellow potassium chromate solution turns it orange, and adding base reverses it, demonstrating Le Chatelier's principle.

Importancia industrial

El equilibrio cromato/dicromato es importante en el cromado, el curtido del cuero y en la comprensión de la contaminación ambiental por Cr(VI).

Propiedades

Tipo: Redox
Reversible: Sí
Energía: Exotérmico
ΔH: -14,0 kJ/mol

Reacciones relacionadas

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) Chlorine Oxidation of Bromide Copper Oxidation by Nitric Acid Hypochlorite Oxidation of Hydrogen Peroxide Hydrogen Peroxide as Oxidizing Agent (Acidic) 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.