Hexane is an organic compound, a straight-chain alkane with six carbon atoms with the molecular formula C6H14. It is an odourless and colourless liquid, when pure, and it has a boiling point of approximately 69 °C (156 °F). It can be used widely as a relatively safe, largely unreactive, cheap, and easily evaporated non-polar solvent.
Hexane is a significant gasoline constituent. At times, it refers to a mixture, which is composed largely (> 60%) of hexane, with differential amounts of the isomeric compounds: 2-methyl pentane, 3-methyl pentane, and, possibly, the smaller amounts of non-isomeric C5, C6, C7 alkanes (cyclo). Hexane is one of the cheaper compounds and is often used in large-scale operations without requiring a single isomer (a cleaning solvent or for chromatography, as an example).
The other names of hexane can be given as 1-Hexanol, Amyl Carbinol, 1-Hydroxyhexane, and Hexyl alcohol.
Properties of Hexane
The physical properties of Hexane - C6H14 are as follows.
Physical Properties of Hexane
The chemical properties of Hexane - C6H14 are as follows.
Chemical Properties of Hexane - C₆H₁₄
2C6H14 + 19O2 → 12CO2 + 14H2O
C6H14 (by thermal cracking) → C4H10 (called butane) + C2H4 (called ethene)
Hexane Structure - C₆H₁₄
The structure of Hexane can be represented as follows.
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Production of Hexane
Hexanes are obtained chiefly by crude oil refining. This fraction's exact composition largely depends on the oil source (reformed or crude) and the refining constraints. The industrial product (in general, around 50% by straight-chain isomer weight) is given as the fraction boiling at 65-70 °C (149-158 °F).
Use of Hexane
Industrially, hexanes can be used in the formulation of glues for shoes, roofing, and leather products. They can also be used to extract cooking oils (like soy oil or canola oil) from seeds, for degreasing and cleaning a variety of items, and in the manufacturing of textiles. Commonly, in the United States, they are used in the food-based soybean oil extraction, and also they are potentially present as contaminants in all those soy food products where the technique can be used; the lack of regulation by the FDA (Food and Drug Administration, the USA) of this contaminant is some controversy matter.
One of the typical laboratory hexanes uses is to extract grease and oil contaminants from water and soil for analysis. Since the hexane solvent or hexane compound cannot be easily deprotonated, it can be used in the laboratory for reactions, involving the stronger bases, like the organolithiums preparation. As an example, typically, butyllithiums are supplied as a hexane solution.
In general, hexanes are used as a non-polar solvent in chromatography. Higher alkanes exist as impurities in hexanes contain the same retention times as that of solvent, which means that the fractions containing hexane also contain these impurities. In the case of preparative chromatography, the large volume of hexane concentration can result in a sample, which is appreciably contaminated by alkanes. This can result in a solid compound being obtained as an oil, and the alkanes may interfere with the analysis.
Hexane's acute toxicity is rather low. Inhaling n-hexane or hexane n at 5000 ppm for just 10 minutes produces marked vertigo. If it is 2500-1000 ppm for 12 hours, it can produce fatigue, appetite loss, drowsiness, paresthesia in the distal extremities. If 2500–5000 ppm, it can produce cold pulsation in the extremities, muscle weakness, headache, anorexia, and blurred vision.
Chronic occupational exposure to the elevated levels of n-hexane or hexane n has been described to be associated with neurotoxicity in workers in printing presses, peripheral neuropathy in auto mechanics in the United States, furniture and shoe factories in Europe, Asia, and North America.
At times, n-Hexane is allowed for various usages like, as a denaturant for alcohol, cleaning agents in the textile, furniture, and leather industries.
Similar to gasoline, hexane is also highly volatile, and it is an explosion risk.
Intermolecular Forces of Hexane
Hexane is a non-polar molecule because of 2 factors. Firstly, it has the only bond as C-H, which is non-polar due to hydrogen and carbon having many similar electronegativities. Secondly, hexane is symmetric, and hence, any polarity in the molecule would eliminate out. Thus, the only intermolecular force acts in hexane are the van der Waals forces/London Dispersion forces or the induced dipole-dipole forces.
Where these are caused by the electrons present in hexane repelling electrons in neighboring hexane molecules, hence inducing a small positive dipole or charge, which then interacts with electron-dense areas in the original molecule.
Did You Know?
Hexane is a strong solvent when we are trying to dissolve a non-polar compound. However, if we try to use a hexane solvent to dissolve a polar compound, it would be highly unsuccessful. Water would be a safer option than hexane with a polar compound because water is polar, and it can interact more readily with any polar compound.