2,2,4-Trimethylpentane

  • Isooctane
  • Isobutyltrimethylmethan

Colorless, gasoline -like odor liquid

Liquid

0.69 g · cm -3

-107 ° C

99 ° C.

52 hPa ( 20 ° C)

Very poor in water ( 0.56 mg · l-1 at 25 ° C)

1.3884 (25 ° C)

Risk

Not determined, as possibly carcinogenic

Template: Infobox chemical / molecular formula search available

8.6 kWh / L = 12.5 kWh / kg

100 RON ( by definition )

-12 ° C.

2,2,4 trimethylpentane ( commonly called isooctane) is a colorless liquid compound which belongs to the chemical group of saturated, branched hydrocarbons ( alkanes). It is an isomer of octane. With the help of 2,2,4- trimethylpentane the scale of octane numbers has been set, a measure of the antiknock properties of gasoline fuel. 2,2,4- trimethylpentane is thereby assigned, by definition, the octane number 100.

Production and representation

2,2,4- trimethylpentane is obtained by dimerization and subsequent hydrogenation of butylene or butylene, and isobutane.

Properties

2,2,4- trimethylpentane is a colorless liquid with a gasoline- like odor. The boiling point at atmospheric pressure at 99 ° C. The heat of vaporization of 30.79 kJ · mol -1. The vapor pressure function is given by Antoine corresponding log10 (P) = A- ( B / ( T C )) ( P in bar, T in K) with A = 3.93679, B = 1257.840 and C = -52.415 in temperature range from 297.5 K to 373.3 K. the critical temperature Tc = 270.65 ° C, the critical pressure pc = 25.7 bar and an acentric factor? c = 0.30346 are known as critical data. The solubility in water is extremely low at 25 ° C with 2.2 × 10-4 Ma %. Conversely, dissolve at 25 ° C only 0.011 % by mass of water in 2,2,4- trimethylpentane. The compound is a number of other solvent azeotropically boiling mixtures. The azeotropic compositions and boiling points are given in the following table. No azeotropes are formed with n-heptane, n- octane, cyclohexane, toluene, ethylbenzene, and tetrachloromethane.

Of all the octane isomers has the connection to -12 ° C the lowest flash point. The ignition temperature is 418 ° C.

Use

  • Improve the antiknock in petrol
  • Jet fuel ( calorific value 44.7 MJ / kg)
  • Solvent for paints
  • Is used for the production of oil ( such as for candles) or certain types of polyethylene
  • Carrier / matrix for chemical analysis, especially in the petrochemical
CAS registry number PubChem Dangerous Substances Directive (67/548/EEC) Heat of combustion#Lower heating value Flammability limit Antoine equation Critical point (thermodynamics) Isopropyl alcohol 2-Butanol Acetonitrile CRC Handbook of Chemistry and Physics Digital Object Identifier
7975
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