Naphthalene
|  | |||
| Names | |||
|---|---|---|---|
| IUPAC name Naphthalene | |||
| Other names white tar, camphor tar, tar camphor, naphthalin, naphthaline, antimite, albocarbon, hexalene, mothballs, moth flakes | |||
| Identifiers | |||
| 3D model (JSmol) | |||
| 1421310 | |||
| ChEBI | |||
| ChEMBL | |||
| ChemSpider | |||
| ECHA InfoCard | 100.001.863 | ||
| EC Number | 
 | ||
| 3347 | |||
| KEGG | |||
| PubChem CID | |||
| RTECS number | 
 | ||
| UNII | |||
| CompTox Dashboard (EPA) | |||
| 
 | |||
| 
 | |||
| Properties | |||
| C10H8 | |||
| Molar mass | 128.174 g·mol−1 | ||
| Appearance | White solid crystals/ flakes | ||
| Odor | Strong odor of coal tar or mothballs | ||
| Density | 1.145 g/cm3 (15.5 °C) 1.0253 g/cm3 (20 °C) 0.9625 g/cm3 (100 °C) | ||
| Melting point | 78.2 °C (172.8 °F; 351.3 K) 80.26 °C (176.47 °F; 353.41 K) at 760 mmHg | ||
| Boiling point | 217.97 °C (424.35 °F; 491.12 K) at 760 mmHg | ||
| 19 mg/L (10 °C) 31.6 mg/L (25 °C) 43.9 mg/L (34.5 °C) 80.9 mg/L (50 °C) 238.1 mg/L (73.4 °C) | |||
| Solubility | Soluble in alcohols, liquid ammonia, Carboxylic acids, C6H6, SO2, CCl4, CS2, toluene, aniline | ||
| Solubility in ethanol | 5 g/100 g (0 °C) 11.3 g/100 g (25 °C) 19.5 g/100 g (40 °C) 179 g/100 g (70 °C) | ||
| Solubility in acetic acid | 6.8 g/100 g (6.75 °C) 13.1 g/100 g (21.5 °C) 31.1 g/100 g (42.5 °C) 111 g/100 g (60 °C) | ||
| Solubility in chloroform | 19.5 g/100 g (0 °C) 35.5 g/100 g (25 °C) 49.5 g/100 g (40 °C) 87.2 g/100 g (70 °C) | ||
| Solubility in hexane | 5.5 g/100 g (0 °C) 17.5 g/100 g (25 °C) 30.8 g/100 g (40 °C) 78.8 g/100 g (70 °C) | ||
| Solubility in butyric acid | 13.6 g/100 g (6.75 °C) 22.1 g/100 g (21.5 °C) 131.6 g/100 g (60 °C) | ||
| log P | 3.34 | ||
| Vapor pressure | 8.64 Pa (20 °C) 23.6 Pa (30 °C) 0.93 kPa (80 °C) 2.5 kPa (100 °C) | ||
| Henry's law constant (kH) | 0.42438 L·atm/mol | ||
| −91.9·10−6 cm3/mol | |||
| Thermal conductivity | 98 kPa: 0.1219 W/m·K (372.22 K) 0.1174 W/m·K (400.22 K) 0.1152 W/m·K (418.37 K) 0.1052 W/m·K (479.72 K) | ||
| Refractive index (nD) | 1.5898 | ||
| Viscosity | 0.964 cP (80 °C) 0.761 cP (100 °C) 0.217 cP (150 °C) | ||
| Structure | |||
| Monoclinic | |||
| P21/b | |||
| C5 2h | |||
| a = 8.235 Å, b = 6.003 Å, c = 8.658 Å α = 90°, β = 122.92°, γ = 90° | |||
| Thermochemistry | |||
| Heat capacity (C) | 165.72 J/mol·K | ||
| Std molar entropy (S⦵298) | 167.39 J/mol·K | ||
| Std enthalpy of formation (ΔfH⦵298) | 78.53 kJ/mol | ||
| Gibbs free energy (ΔfG⦵) | 201.585 kJ/mol | ||
| Std enthalpy of combustion (ΔcH⦵298) | −5156.3 kJ/mol | ||
| Hazards | |||
| Occupational safety and health (OHS/OSH): | |||
| Main hazards | Flammable, sensitizer, possible carcinogen. Dust can form explosive mixtures with air | ||
| GHS labelling: | |||
| Danger | |||
| H228, H302, H351, H410 | |||
| P210, P273, P281, P501 | |||
| NFPA 704 (fire diamond) | |||
| Flash point | 80 °C (176 °F; 353 K) | ||
| 525 °C (977 °F; 798 K) | |||
| Explosive limits | 5.9% | ||
| Threshold limit value (TLV) | 10 ppm (TWA), 15 ppm (STEL) | ||
| Lethal dose or concentration (LD, LC): | |||
| LD50 (median dose) | 1800 mg/kg (rat, oral) 490 mg/kg (rat, intravenous) 1200 mg/kg (guinea pig, oral) 533 mg/kg (mouse, oral) | ||
| NIOSH (US health exposure limits): | |||
| PEL (Permissible) | TWA 10 ppm (50 mg/m3) | ||
| REL (Recommended) | TWA 10 ppm (50 mg/m3) ST 15 ppm (75 mg/m3) | ||
| IDLH (Immediate danger) | 250 ppm | ||
| Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references | |||
Naphthalene is an organic compound with formula C
10H
8. It is the simplest polycyclic aromatic hydrocarbon, and is a white crystalline solid with a characteristic odor that is detectable at concentrations as low as 0.08 ppm by mass. As an aromatic hydrocarbon, naphthalene's structure consists of a fused pair of benzene rings. It is the main ingredient of traditional mothballs.