| Physical Description |
Nitric acid, red fuming appears as a pale yellow to reddish brown liquid generating red-brown fumes and having a suffocating odor. Very toxic by inhalation. Corrosive to metals or tissue. Prolonged exposure to low concentrations or short term exposure to high concentrations may result in adverse health effects. Rate of onset: Immediate Persistence: Hours - days Odor threshold: ~1 ppm Source/use/other hazard: Used in many industries; Very corrosive to skin/mucous membranes as well as metals & other materials. |
| Color/Form |
Transparent, colorless, or yellowish, fuming, hygroscopic, corrosive liquid |
| Odor |
Characteristic choking odor |
| Taste |
1.1X10+3 N detection level in water. /Purity not specified/ |
| Boiling Point |
181 °F at 760 mmHg (NIOSH, 2023) |
| Melting Point |
-44 °F (NIOSH, 2023) |
| Solubility |
Miscible (NIOSH, 2023) |
| Density |
1.5 at 77 °F (NIOSH, 2023) - Denser than water; will sink |
| Vapor Density |
Relative vapor density (air = 1): 2.2 |
| Vapor Pressure |
48 mmHg (NIOSH, 2023) |
| LogP |
-0.21 |
| Decomposition |
On exposure to atmospheric humidity or heat there is decomposition with the formation of nitrogen peroxide. |
| Viscosity |
1.092 mPa.s at 0 °C; 0.746 mPa.s at 25 °C; 0.617 mPa.s at 40 °C |
| Corrosivity |
IN PRESENCE OF TRACES OF OXIDES IT ATTACKS ALL BASE METALS EXCEPT ALUMINUM & SPECIAL CHROMIUM STEELS |
| Heat of Vaporization |
Molar enthalpy of vaporization: 39.1 kJ/mol at 25 °C |
| Surface Tension |
0.04356 N/m at 0 °C; 0.04115 N/m at 20 °C; 0.03776 N/m at 40 °C |
| Ionization Potential |
11.95 eV |
| Odor Threshold |
Odor Threshold Low: 0.27 [mmHg] Odor threshold from AIHA |
| Refractive Index |
Index of refraction: 1.393 at 125 °C/D |
| Dissociation Constants |
pKa = -1.38 |
| Other Experimental Properties |
Heat of infinite dilution at 298.1 K: -7971 cal/mole; forms azeotrope with water so-called constant boiling acid at 68% nitric acid, bp: 120.5 °C, density 1.41 at 20 °C/4 °C; Heat of Fusion: 2.503 kcal/mole; Density at -41.6 °C (solid): 1895 |
| Chemical Classes |
Toxic Gases & Vapors -> Acids, Inorganic |
