Key Difference – Hexane vs Cyclohexane
Even though, both hexane and cyclohexane are from the alkane family, their physical and chemical properties are not similar. The key difference between hexane and cyclohexane is that hexane is an acyclic alkane while cyclohexane is a cyclic alkane with a ring structure. They both have six carbon atoms, but a different number of hydrogen atoms. This leads to the differences in their molecular structure and other properties. Both are used as organic solvents, but the other industrial application is unique to both of them.
What is Hexane?
Hexane (also known as n-hexane) is a colorless, clear, highly volatile, flammable organic liquid with petroleum-like odor. It is an aliphatic hydrocarbon that is produced as a byproduct from the crude oil refining process. It is insoluble in water and less dense than water, but its vapor is heavier than air. Hexane is highly reactive with certain chemicals including liquid chlorine, concentrated oxygen, and sodium hypochlorite. It is a hazardous chemical and causes acute and chronic health problems depending on the exposure.
What is Cyclohexane?
Cyclohexane is a cyclic alkane with a single ring structure. It is a clear, colorless, non-polar organic liquid with a mild, sweet gasoline like odor that is widely used as a solvent in chemical laboratories. Cyclohexane is a harmful and hazardous compound for both human and animals, and also it is considered as an environmental hazard. It is water insoluble liquid, but dissolves in methanol, ethanol, ether, acetone, benzene, ligroin, carbon tetrachloride.
What is the difference between Hexane and Cyclohexane?
Molecular Formula and Structure:
Hexane: The molecular formula of hexane is C6H14 and it is considered as a saturated hydrocarbon. It has a straight chain molecular structure as shown earlier.
Cyclohexane: The molecular formula of cyclohexane is C6H12. It possesses a ring structure having all the carbon atoms similar bonds. Each carbon atom is bonded to another two carbon atoms and two hydrogen atoms. Cyclohexane is unsaturated hydrocarbon molecule.
Hexane: Hexane is widely used as a solvent to extract edible oils from vegetables and seeds, and as well as a cleaning agent. It is also used to manufacture thinner in the paint industry and used as a chemical reaction medium.
Cyclohexane: Pure cyclohexane is commonly used as a solvent; in addition, it is used in nylon industry to produce precursors such as adipic acid and caprolactam, to produce paint removers and other chemicals.
Hexane: The exposure to hexane causes both acute (short-term) and chronic (long-term) problems depending on the exposure level and the time. If a person inhales high levels of hexane for a short period, it can cause mild central nervous system (CNS) effects such as dizziness, giddiness, slight nausea, and headache. Chronic exposure to hexane in the air causes polyneuropathy in humans, with numbness in the extremities, muscular weakness, blurred vision, headache, and fatigue. There is no evidence found that it has carcinogenic effects in humans or animals.
Cyclohexane: It is a toxic chemical; inhalation of cyclohexane causes headache, dizziness, drowsiness, incoordination, and euphoria. Ingestion may cause nausea, vomiting and occasionally diarrhea. Dermal exposure causes irritation of the skin and severe problems such as drying and cracking can happen due to defatting action if it contacts more often or over a so long period. Ocular exposure results in serious problems such as pain, blepharospasm (involuntary tight closure of the eyelids), lacrimation(lubricating the eyes in response to an irritation), conjunctivitis(inflammation of the conjunctiva of the eye), palpebral oedema (swelling of the eyelids) and photophobia (extreme sensitivity to light).
1. Hexane-2D-flat-A By Ben Mills (Own work) [Public domain], via Wikimedia Commons
2. Cyclohexane with H By Calvero. (Selfmade with ChemDraw.) [Public domain], via Wikimedia Commons