Naphthalene
Preferred IUPAC name Naphthalene
Systematic name Bicyclo[4.4.0]deca-1,3,5,7,9-pentaene
Other names	white tar, camphor tar, tar camphor, naphthalin, naphthaline, antimite, albocarbon, hexalene, mothballs, moth flakes
Identifiers
CAS number	91-20-3
PubChem	931
EC number	214-552-7
KEGG	C00829
ChEBI	CHEBI:16482
RTECS number	QJ0525000
SMILES	c1ccc2ccccc2c1
InChI InChI=1/C10H8/c1-2-6-10-8-4-3-7-9(10)5-1/h1-8H
Beilstein Reference	1421310
Gmelin Reference	3347
Properties
Molecular formula	C10H8
Molar mass	128.17 g mol-1
Appearance	White solid crystals/ flakes
Odor	Strong odor of coal tar
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, 351 K, 173 °F
Boiling point
Solubility in water	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)
kH	0.42438 L·atm/mol
Magnetic susceptibility (χ)	-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
Crystal structure	Monoclinic
Space group	P21/b
Point group	C52h
Lattice constant	a = 8.235 Å, b = 6.003 Å, c = 8.658 Å
Thermochemistry
Std enthalpy of formation ΔfHo298	78.53 kJ/mol
Std enthalpy of combustion ΔcHo298	-5156.3 kJ/mol
Standard molar entropy So298	167.39 J/mol·K
Specific heat capacity, C	165.72 J/mol·K
Hazards
Main hazards	Flammable, sensitizer, possible carcinogen. Dust can form explosive mixtures with air
NFPA 704	2 2 0
Explosive limits	5.9%
U.S. Permissible exposure limit (PEL)	TWA 10 ppm (50 mg/m3)
Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)

Naphthalene is a crystalline, white hydrocarbon, with a strong smell. It is best known as the main ingredient in mothballs, urinal deodorizer blocks, and can be used as an antiseptic. In mothballs, it is used as an insecticide or pesticide.

Naphthalene is toxic. In humans, being exposed to naphthalene can destroy red blood cells. Naphthalene may also cause cancer.