ABSTRACT
Note: According to Chevron Phillips Company’s (2004) Technical Data Sheet, 99.0-99.4 wt % 3methylpentane contains 2-methylbutane (0.3 wt %) and n-hexane (0.3 wt %). CASRN: 96-14-0; DOT: 2462; DOT label: Combustible liquid; molecular formula: C6H14; FW: 86.18; RTECS: SA2995500 Physical state, color, and odor: Clear, colorless, flammable liquid with an odor similar to hexane, heptane, and similar aliphatic hydrocarbons. An odor threshold concentration of 8.9 ppmv was reported by Nagata and Takeuchi (1990). Melting point (°C): -117.8 (Exxon Corp., 1985) Boiling point (°C): 63.26 (Tu et al., 2001) Density (g/cm3): 0.66431 at 20 °C (Dreisbach, 1959) 0.64954 at 25.00 °C (Bouzas et al., 2000) 0.65960 at 25.00 °C (Tu et al., 2001) Diffusivity in water (x 10-5 cm2/sec): 0.76 at 20 °C using method of Hayduk and Laudie (1974) Dissociation constant, pKa: >14 (Schwarzenbach et al., 1993) Flash point (°C): <-6.6 (Hawley, 1981) Lower explosive limit (%): 1.2 (NFPA, 1984) Upper explosive limit (%): 7.0 (NFPA, 1984) Entropy of fusion (cal/mol⋅K): 12.53 (Douslin and Huffman, 1946) Heat of fusion (kcal/mol): 1.2675 (quoted, Riddick et al., 1986) Henry’s law constant (atm⋅m3/mol): 1.693 at 25 °C (Hine and Mookerjee, 1975)
49.9 at 25 °C (quoted, Freitas et al., 1997) Ionization potential (eV): 10.04 (Lias and Liebman, 1998) 10.30 (Collin and Lossing, 1959) 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: 2.88 (Coates et al., 1985) Solubility in organics: In methanol, g/L: 389 at 5 °C, 450 at 10 °C, 530 at 15 °C, 650 at 20 °C, 910 at 25 °C. Miscible at higher temperatures (Kiser et al., 1961). Solubility in water: 10.5 mg/L at 23 °C (Coates et al., 1985) 13.1 mg/kg at 25 °C (shake flask-GLC, Price, 1976) 12.8 mg/kg at 25 °C (shake flask-GC, McAuliffe, 1966) 21.5 mg/kg at 0 °C, 17.9 mg/kg at 25 °C (shake flask-GC, Polak and Lu, 1973) Vapor density: 3.52 g/L at 25 °C, 2.98 (air = 1) Vapor pressure (mmHg): 217.8 at 23.2 °C (Willingham et al., 1945) Environmental fate: Photolytic. The following rate constants were reported for the reaction of 3-methylpentane and OH radicals in the atmosphere: 4.30 x 10-9 cm3/molecule⋅sec at 300 K (Darnall et al., 1976); 6.8 x 10-12 cm3/molecule⋅sec at 305 K (Darnall et al., 1978); 5.7 x 10-12 cm3/molecule⋅sec (Altshuller, 1991). Chemical/Physical. Complete combustion in air produces carbon dioxide and water vapor. 3Methylpentane will not hydrolyze because it does not contain a hydrolyzable functional group. Exposure limits: ACGIH TLV: TWA and STEL for all isomers except n-hexane are 500 and 1,000 ppm, respectively (adopted). Symptoms of exposure: Inhalation of vapors may cause irritation to respiratory tract. Narcotic at high concentrations (Patnaik, 1992). Source: Schauer et al. (1999) reported 3-methylpentane in a diesel-powered medium-duty truck exhaust at an emission rate of 670 µg/km. California Phase II reformulated gasoline contained 3-methylpentane at a concentration of 22.7 g/kg. Gas-phase tailpipe emission rates from gasoline-powered automobiles with and without catalytic converters were 3.76 and 512 mg/km, respectively (Schauer et al., 2002). Uses: Solvent; gasoline component; organic synthesis.
