CAS 7697-37-2 · Strong Oxidizing Mineral Acid
Nitric Acid
HNO₃ · MW 63.01 g/mol · Strong Oxidizer
A highly corrosive, strongly oxidizing mineral acid used across fertilizer production, metal processing, electronics manufacturing, and analytical chemistry. Nitric acid's oxidizing power distinguishes it from other mineral acids — it dissolves metals that resist HCl and H₂SO₄, and nitrates organic compounds for explosives and pharmaceutical synthesis. Texas-Chem supplies HNO₃ in dilute, concentrated, and fuming grades.
Formula
HNO₃
Boiling Point
83 °C (68%)
pH (1%)
<1.0
Grades
Dilute · Conc. · Fuming
Structural Formula
Strong acid and powerful oxidizer — the nitro group enables nitration of organic compounds
Safety & Regulatory
- NFPA Health
- 4 — Severe hazard
- NFPA Flammability
- 0 — Non-flammable
- NFPA Reactivity
- 3 — Severe hazard (oxidizer)
- OSHA PEL (TWA)
- 2 ppm (5 mg/m³)
- ACGIH TLV-TWA
- 2 ppm
- ACGIH TLV-STEL
- 4 ppm
- DOT Hazard Class
- 8 — Corrosive / 5.1 Oxidizer
- UN Number
- UN 2031 (conc.) / UN 2032 (fuming)
Extremely corrosive and oxidizing — causes severe burns and ignites organic materials. Full acid PPE required. SDS available upon request.
Grades & Packaging
Available Grades
Pack Sizes
Physical & Chemical Properties
| Molecular Formula | HNO₃ |
| Molecular Weight | 63.01 g/mol |
| CAS Number | 7697-37-2 |
| Boiling Point | 83 °C (68% solution) |
| Melting Point | −42 °C (pure) |
| Flash Point | Non-flammable (strong oxidizer) |
| Density | 1.41 g/cm³ (68% solution) |
| Vapor Pressure | 6.4 kPa at 20 °C (68%) |
| Solubility | Miscible with water in all proportions |
| pH (1% solution) | <1.0 |
| Color | Colorless to pale yellow (fuming: red-brown) |
| Auto-ignition Temp. | Non-flammable — strong oxidizer |
Industrial Applications
Fertilizer Production (Ammonium Nitrate)
Over 80% of global nitric acid production goes to fertilizer manufacture. Nitric acid reacts with ammonia to produce ammonium nitrate — a high-nitrogen fertilizer and explosive precursor.
Metal Etching & Passivation
Etching agent for copper, brass, and stainless steel in electronics and metalworking. Nitric acid passivates stainless steel by dissolving surface iron and promoting a protective chromium oxide layer.
Explosives & Propellants
Nitration agent for producing TNT, nitroglycerin, RDX, and nitrocellulose. Mixed acid (HNO₃ + H₂SO₄) is the standard nitrating mixture for aromatic compounds.
Printed Circuit Board Manufacturing
Etchant for copper in PCB fabrication. Nitric acid selectively dissolves copper while leaving the substrate intact, enabling precise circuit pattern definition.
Analytical Chemistry
Digestion acid for dissolving metals and alloys prior to ICP-MS, AAS, and other elemental analysis techniques. Nitric acid oxidizes organic matter and dissolves most metals without introducing chloride interference.
Stainless Steel Pickling
Component of mixed acid pickling baths (HNO₃ + HF) for removing heat tint and scale from stainless steel after welding and heat treatment. Restores corrosion resistance of the passivated surface.
Why Source Nitric Acid from Texas-Chem?
- 35+ years supplying industrial acids to Texas manufacturers
- Dilute, concentrated, and fuming grades available
- Proper oxidizer-rated packaging and placarding
- Competitive pricing backed by top-tier producer relationships
- Technical support and SDS documentation with every order
- Same-day quotes for standard quantities