Pentane

Pentane is an organic compound, an alkane with 5 carbon atoms. It is composed of three isomers, n-pentane, isopentane (or methylbutane) and neopentane. While the term "pentane" may refer to any of the isomers, the IUPAC nomenclature specifies that the term must only be used for the n isomer.

Properties

Chemical

Pentane, like other hydrocarbons, will burn in air when ignited by an open flame to release carbon dioxide and water vapor.

Physical

Pentane is a colorless liquid hydrocarbon, with a characteristic smell. It is insoluble in water, but miscible with other organic solvents. It has a density of 0.621 g/cm³, meaning it's lighter than water. It boils at 36°C and melts at -130°C.

Its isomer neopentane, though, is a gas that boils at 9.5°C, is the heaviest and the most high-boiling of all hydrocarbon gases.

Availability

Pentane can be purchased form chemical suppliers. Certain pesticides contain pentane.

Preparation

Pentane can be prepared by reducing pentane derivates.

Projects

• Extraction (solvent)
• Phthalic and maleic anhydride synthesis

Handling

Safety

Pentane evaporates very fast and the vapors are hazardous if inhaled, work should be performed in a fumehood or outside. If pentane is inhaled in large amounts, further exposure should be limited and one should seek fresh air.

Storage

Due to its low boiling point, pentane should be stored in closed glass bottles, at constant temperature, away from any source of heat, even small ones. If it's stored at low temperatures, and then brought at room temperatures or slightly higher, pressure will build up in the bottle from the vapors and the bottle can explode. It is mandatory to open the bottle from time to time, to release the pressure.

Commercial pentane contains small amounts of inhibitors, that prevent its degradation, over long periods of time. They can be removed by distillation, as their boiling point is much higher than that of pentane.

Disposal

Pentane can be safely burned, as it theoretically should not generate any toxic byproducts. However, like other hydrocarbons, carbon monoxide can be formed so this should not be performed indoors.