Copper Oxidation by Nitric Acid

3Cu + 8HNO3(dilute) → 3Cu(NO3)2 + 2NO + 4H2O

Aperçu

Dilute nitric acid oxidizes copper to Cu²⁺ while the nitrate ion is reduced to nitric oxide (NO) gas. Unlike HCl or H₂SO₄(dilute), nitric acid can dissolve copper because the nitrate ion acts as the oxidizing agent. The solution turns blue from Cu(NO₃)₂ and the NO gas oxidizes in air to brown NO₂.

Participants

Rôle Substance Coefficient État
Réactif Copper Cu 3 (s)
Réactif Nitric Acid HNO₃ 8 (aq)
Produit Water H₂O 4 (l)

Exemple du quotidien

Chemistry students observe this reaction as a dramatic demonstration where copper dissolves in HNO₃ with brown fumes forming above the solution.

Importance industrielle

Copper dissolution in nitric acid is used in analytical chemistry, in copper etching for printed circuit board manufacturing, and in metal refining.

Propriétés

Type
Redox
Réversible
Non
Énergie
Exothermique
ΔH
-135,0 kJ/mol

Réactions associées

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 Hypochlorite Oxidation of Hydrogen Peroxide Hydrogen Peroxide as Oxidizing Agent (Acidic) Zinc Reduction of Silver Ion Displacement of Hydrogen from Acid by Magnesium

Frequently Asked Questions

What is the equation for Copper Oxidation by Nitric Acid?
The balanced equation is: 3Cu + 8HNO₃(dilute) → 3Cu(NO₃)₂ + 2NO + 4H₂O.
What type of reaction is Copper Oxidation by Nitric Acid?
Copper Oxidation by Nitric Acid is a redox reaction.
Is Copper Oxidation by Nitric Acid exothermic or endothermic?
Copper Oxidation by Nitric Acid is exothermic (releases energy). The enthalpy change (ΔH) is -135.0 kJ/mol.