Cyclohexane – C6H12, 110-82-7

Cyclohexane or n-Hexahydrobenzene is a cyclic hydrocarbon with a molecular formula of C6H12. It is a colorless, flammable liquid commonly used as a solvent and as a starting material in the production of synthetic materials.

IUPAC NameCyclohexane
Molecular FormulaC6H12
CAS number110-82-7
SynonymsCyclohexan, n-Hexahydrobenzene
InChIInChI=1S/C6H12/c1-2-4-6-5-3-1/h1-6H2

Cyclohexane Properties

Cyclohexane Density

Cyclohexane has a density of 0.779 g/mL, which is relatively low compared to other organic compounds. This low density is due to its low molecular weight and nonpolar nature.

Cyclohexane Boiling Point

Cyclohexane has a boiling point of 80.7 °C (177.3 °F). It is a relatively low boiling point compared to other organic compounds due to its molecular structure, which lacks any polar functional groups that would increase its surface tension.

Cyclohexane Molar Mass

The molar mass of cyclohexane is 84.16 g/mol. It is calculated by adding up the atomic masses of all the atoms in the molecular formula of cyclohexan, which is C6H12.

Cyclohexane Melting Point

The melting point of cyclohexane is 6.5 °C (43.7 °F). This low melting point is a result of its nonpolar nature, which reduces the intermolecular forces between its molecules.

Cyclohexane Molecular Weight

Cyclohexane

The molecular weight of n-Hexahydrobenzene is 84.16 g/mol, which is calculated from its molecular formula, C6H12.

n-Hexahydrobenzene Structure

Cyclohexane is a six-carbon ring structure composed of hexagonal hydrocarbons. Its molecular structure is flat and nonpolar, which allows it to dissolve other nonpolar substances, but not polar ones. The ring shape of n-Hexahydrobenzene is crucial in its properties, such as its low melting and boiling points, low surface tension, and low reactivity.

AppearanceColorless Liquid
Specific Gravity0.779 g/mL
ColorColorless
OdorMild Hydrocarbon Odor
Molar Mass84.16 g/mol
Density0.779 g/mL
Melting Point6.5 °C (43.7 °F)
Boiling Point80.7 °C (177.3 °F)
Flash PointNot Available
Water SolubilityInsoluble
SolubilitySoluble in Non-Polar Solvents
Vapour PressureNot Available
Vapour DensityNot Available
pKaNot Available
pHNot Available

Cyclohexane Safety and Hazards

Cyclohexane is a flammable liquid and vapor, and contact with fire or sparks can cause an explosion. Inhalation of its vapor or mist can cause headaches, dizziness, and drowsiness, while skin contact can cause irritation and defatting. It should be handled with caution and in accordance with proper safety procedures. Proper protective equipment, including gloves and eye protection, should be worn when handling n-Hexahydrobenzene.

Hazard SymbolsFlammable Liquid
Safety DescriptionS16, S26, S36/37/39, S45
UN IDsUN1098
HS Code2902.90.90
Hazard Class3
Packing GroupII
ToxicityIrritating to eyes, skin, and respiratory system. May cause drowsiness or dizziness if inhaled.

Cyclohexane Synthesis Methods

n-Hexahydrobenzene can be synthesized by several methods, including the following:

  • Cyclohexanone Oxidation: Cyclohexanone can be oxidized to produce n-Hexahydrobenzene, typically using a strong oxidizing agent such as potassium permanganate or chromic acid.
  • Benzene Hydrogenation: Benzene can be hydrogenated in the presence of a catalyst, such as nickel or palladium, to produce n-Hexahydrobenzene.
  • Toluene Cyclodehydrogenation: Toluene can be cyclodehydrogenated in the presence of a catalyst, such as sulfuric acid, to produce n-Hexahydrobenzene.
  • Fischer Indole Synthesis: n-Hexahydrobenzene can be synthesized by a reaction between a ketone and an aldehyde in the presence of an acid catalyst.
  • Alkaline Hydrogenation of Phenol: Phenol can be hydrogenated in the presence of an alkaline catalyst to produce n-Hexahydrobenzene.

These methods can be optimized for different applications based on factors such as yield, selectivity, and cost, among others.

Cyclohexane Uses

n-Hexahydrobenzene is a versatile chemical that has a range of industrial applications. Some of its common uses include:

  • Solvent: Use n-Hexahydrobenzene to dissolve many organic compounds including fats, oils, waxes, resins, rubber, and cellulose.
  • Intermediate: Employ n-Hexahydrobenzene as an intermediate in the synthesis of chemicals such as cyclohexanone, adipic acid, and caprolactam.
  • Fuel Additive: Enhance the quality of gasoline and diesel fuels with the use of n-Hexahydrobenzene as a fuel additive.
  • Cleaning Agent: Utilize cyclohexane as a cleaning agent in the electronics and aerospace industries.
  • Adhesives: Dissolve adhesives and resins with cyclohexane.
  • Pesticides: Apply n-Hexahydrobenzene as a solvent in the production of some pesticides.

Rubber Manufacturing: Employ n-Hexahydrobenzene as a solvent in the manufacturing of synthetic rubbers.

Cyclohexane should only be used for its intended purposes and in accordance with proper safety procedures and regulations.