Nitric Acid (HNO₃)
Other Names
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Aqua Fortis
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Hydrogen Nitrate
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Nitric(V) acid
CAS Number: 7697-37-2
Chemical Formula: HNO₃
Molecular Weight: 63.01 g/mol
📘 1. Definition
Nitric Acid is a strong, highly corrosive mineral acid used in industrial, laboratory, and chemical processes. It is a colorless or slightly yellow liquid with a sharp, acrid odor. Concentrated nitric acid is a strong oxidizing agent, capable of reacting violently with many organic and inorganic substances. Nitric acid is widely used in the production of fertilizers, explosives, and nitration reactions.
🧪 2. Physical & Chemical Properties
| Property | Value |
|---|---|
| Chemical Formula | HNO₃ |
| Molecular Weight | 63.01 g/mol |
| Appearance | Colorless to yellow liquid (fuming in concentrated form) |
| Odor | Pungent, acrid |
| Boiling Point | 83 °C (68% solution) |
| Melting Point | -42 °C (68% solution) |
| Density | 1.51 g/cm³ (concentrated 68%) |
| Solubility | Miscible with water |
| pH | Strongly acidic |
| Stability | Decomposes on heating; reacts violently with organics and reducing agents |
🧰 3. Applications / Uses
| Industry | Applications |
|---|---|
| Fertilizers | Production of ammonium nitrate and calcium ammonium nitrate |
| Explosives | Nitroglycerin, TNT, and other nitrated explosives |
| Chemical Industry | Nitration reactions, manufacture of dyes, pharmaceuticals, and plastics |
| Metal Processing | Pickling and etching of metals, stainless steel passivation |
| Laboratory Use | Strong acid reagent, oxidizer, standard solution in titrations |
| Electronics & Semiconductors | Etching and cleaning of silicon wafers |
⚠️ 4. Safety & Handling
| Hazard | Details |
|---|---|
| Corrosivity | Extremely corrosive to skin, eyes, and respiratory tract |
| Reactivity | Strong oxidizer; reacts violently with organic materials, metals, and bases |
| Health Hazards | Severe burns, respiratory irritation, eye damage |
| Environmental | Highly toxic to aquatic life; acidic waste can damage ecosystems |
| PPE | Acid-resistant gloves, goggles, face shield, lab coat, fume hood required |
| Storage | Store in cool, dry, well-ventilated area in acid-resistant containers, away from organics, bases, and reducing agents |
| Handling | Avoid contact, inhalation, and spills; neutralize spills with alkaline materials |
📌 5. Summary
Nitric Acid (HNO₃) is a strong, corrosive, and oxidizing acid widely used in fertilizer production, explosives, metal processing, chemical synthesis, and laboratories. Its high reactivity and corrosivity make careful handling, storage, and PPE essential. Proper safety measures are mandatory to prevent accidents, chemical burns, and environmental damage.
