Hexane

Colorless, slightly petrol -like odor liquid

Liquid

0.66 g · cm -3

-95 ° C

69 ° C.

162 hPa ( 20 ° C)

  • Practically insoluble in water (50 mg · l-1 at 20 ° C)
  • Soluble in ethanol, diethyl ether and benzene

1.375 at 20 ° C.

Risk

50 ml · m-3, 180 mg · m-3

25,000 mg · kg -1 ( LD50, rat, oral)

Template: Infobox chemical / molecular formula search available

N-hexane is the alkane (saturated hydrocarbon) associated chemical compound. It is a colorless liquid with the chemical formula C6H14. It is the unbranched isomer of the five hexane isomers.

Properties

Hexane is a colorless, volatile liquid that smells a bit like gasoline. The boiling point at atmospheric pressure is 68.8 ° C. The compound melts at -95.4 ° C. The relative dielectric constant at 20 ° C. 1.8. In water it is practically insoluble. In organic solvents such as alcohols, ethers, benzene, and it is soluble.

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 using cyclohexane, n-pentane, n-heptane, n-octane, toluene, ethylbenzene, xylene, cyclohexanol, diethyl ether, DMF, and carbon disulfide.

Thermodynamic properties

The vapor pressure function is given by Antoine corresponding log10 (P) = A- ( B / ( T C )) ( P in bar, T in K) with A = 3.45604, B = 1044.038 and C = -53 893 in the temperature range of from 177.70 to 264.93 K and A = 4.00266 B = C = -48784 and 1171.530 in the temperature range of 286.18 to 342.69 K.

The temperature dependence of the enthalpy of vaporization can be determined according to equation ΔVH0 = A exp ( - αTr ) (1- Tr) β ( ΔVH0 in kJ / mol, Tr = (T / Tc) reduced temperature ) with A = 43.85 kJ / mol, α = -0.039, β = 0.397 and Tc = 507.4 K describe the temperature range between 298 K and 444 K.

Temperature dependence of the heat of evaporation of n-hexane

Safety characteristics

N- Hexane is highly flammable vapor - air mixtures. The compound has a flash point of -20 ° C. The explosion range is between 1 vol % (35 g/m3) as the lower explosive limit ( LEL) and 8.9 % by volume (319 g/m3 ) and upper explosive limit (UEL ). A correlation of explosion limits with the vapor pressure function yields a lower explosion point of -28 ° C and an upper explosion point of 7 ° C. The explosion limits are pressure dependent. A decrease in the pressure leads to a reduction of the explosion range. The lower explosive limit changes up to a pressure of 100 mbar little and increases only at pressures less than 100 mbar. The upper explosive limit reduced analogously with decreasing pressure.

The limiting oxygen concentration at 20 ° C with 9.1 vol% at 100 ° C at 8.3 vol%. The maximum explosion pressure is 9.5 bar. The marginal gap width was determined to be 0.93 mm. The result is thus a mapping in the explosion group IIA. The ignition temperature is 230 ° C. The fabric falls within the temperature class T3.

Use

Hexane is used in organic chemistry as a solvent and reaction medium in polymerizations, as a diluent for fast drying coatings, printing inks and adhesives and as elution and solvent in the thin layer chromatography. It is still used for the production of plastics and synthetic rubber as well as oil and grease extraction. Since, in contrast to many organic solvents do not attack polystyrene and is highly volatile, it serves as a solvent for polystyrene glue.

Safety

Hexane has addictive potential and is harmful to health. Hexane is hazardous to water ( WGK 2). Hexane is metabolized to 2,5- hexanedione, this leads to nerve damage and is excreted in the urine.

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