ABSTRACT
CH3 CASRN: 589-34-4; molecular formula: C7H16; FW: 100.20 Physical state, color, and odor: Clear, colorless liquid with an odor similar to hexane. An odor threshold concentration of 840 ppbv was reported by Nagata and Takeuchi (1990). Melting point (°C): -119 (Weast, 1986) Boiling point (°C): 91.85 (Wilhoit and Zwolinski, 1971) Density (g/cm3): 0.68713 at 20 °C, 0.68295 at 25 °C (Dreisbach, 1959) Diffusivity in water (x 10-5 cm2/sec): 0.71 at 20 °C using method of Hayduk and Laudie (1974) Dissociation constant, pKa: >14 (Schwarzenbach et al., 1993) Flash point (°C): -3.9 (Hawley, 1981) Henry’s law constant (atm⋅m3/mol): 2.38 at 25 °C (Mackay and Shiu, 1981) Interfacial tension with water (dyn/cm): 50.4 at 25 °C (quoted, Freitas et al., 1997) Soil organic carbon/water partition coefficient, log Koc: Unavailable because experimental methods for estimation of this parameter for aliphatic hydrocarbons are lacking in the documented literature Octanol/water partition coefficient, log Kow: 3.41 (Coates et al., 1985) Solubility in organics: Soluble in acetone, alcohol, benzene, chloroform, ligroin, and ether (Weast, 1986). Miscible with liquid aliphatic hydrocarbons. Solubility in water: 2.90 mg/L at 23 °C (Coates et al., 1985) 2.64 mg/kg at 25 °C (shake flask-GLC, Price, 1976) 5.24 mg/kg at 0 °C, 4.95 mg/kg at 25 °C (shake flask-GC, Polak and Lu, 1973)
4.10 g/L at 25 °C, 3.46 (air = 1) Vapor pressure (mmHg): 61.6 at 25 °C (Wilhoit and Zwolinski, 1971) Environmental fate: Photolytic. Based on a reported photooxidation reaction rate constant of 7.20 x 10-12 cm3/molecule⋅sec with OH radicals, the half-life of 3-methylhexane is 20 h (Altshuller, 1990). Chemical/Physical. Complete combustion in air produces carbon dioxide and water vapor. 3Methylhexane will not hydrolyze because it does not contain a hydrolyzable functional group. Source: Schauer et al. (1999) reported 3-methylhexane in a diesel-powered medium-duty truck exhaust at an emission rate of 310 µg/km. California Phase II reformulated gasoline contained 3-methylhexane at a concentration of 16.2 g/kg. Gas-phase tailpipe emission rates from gasoline-powered automobiles with and without catalytic converters were 2.95 and 415 mg/km, respectively (Schauer et al., 2002). Uses: Oil extender solvent; gasoline component; organic synthesis.
