Nitric Acid Oxidation of Silver
3Ag + 4HNO3(dilute) → 3AgNO3 + NO + 2H2O
Overview
Dilute nitric acid dissolves silver metal, oxidizing it to Ag⁺ while the nitrate is reduced to NO gas. Silver does not dissolve in HCl or H₂SO₄(dilute) because the H⁺ ion cannot oxidize silver, but nitric acid's nitrate ion provides sufficient oxidizing power. This is part of the aqua regia chemistry for noble metals.
Participants
| Role | Substance | Coefficient | State |
|---|---|---|---|
| Reactant | Silver Ag | 3 | (s) |
| Reactant | Nitric Acid HNO₃ | 4 | (aq) |
| Product | Water H₂O | 2 | (l) |
| Product | Silver Nitrate AgNO₃ | 3 | (aq) |
Everyday Example
Jewelers use nitric acid to test whether a piece is real silver, as silver dissolves producing a green solution.
Industrial Importance
Silver dissolution in HNO₃ is the first step in silver refining and in preparing silver nitrate, a key photographic and analytical chemical.
Properties
- Type
- Redox
- Reversible
- No
- Energy
- Exothermic
- ΔH
- -85.0 kJ/mol
Related Reactions
Aqua Regia Dissolving Gold
Bleaching with Sodium Hypochlorite
Cerium(IV) Reduction by Iron(II)
Chlorine Oxidation of Bromide
Chromate-Dichromate Equilibrium
Contact Process SO₂ Oxidation
Copper Displaced by Iron
Copper Oxidation by Nitric Acid
Copper Patina Formation (Verdigris)
Copper Reduction of Silver Ion
Frequently Asked Questions
What is the equation for Nitric Acid Oxidation of Silver?
The balanced equation is: 3Ag + 4HNO₃(dilute) → 3AgNO₃ + NO + 2H₂O.
What type of reaction is Nitric Acid Oxidation of Silver?
Nitric Acid Oxidation of Silver is a redox reaction.
Is Nitric Acid Oxidation of Silver exothermic or endothermic?
Nitric Acid Oxidation of Silver is exothermic (releases energy). The enthalpy change (ΔH) is -85.0 kJ/mol.