Gasoline, also known as gas, petrol or benzin (see below for clarification) is a clear, transparent, viscous petroleum-derived liquid, used primarily as a fuel in internal combustion engines. It consists of various hydrocarbons obtained by the fractional distillation of petroleum, usually enhanced with a variety of additives.
In some countries (such as Czech Republic, Denmark, Germany, Hungary, Netherlands, Romania, Turkey, etc.) the name for gasoline is benzin or a derivative of the term (but NOT benzene), which may lead to confusion over the English meaning of the term, which stands for petroleum ether. Likewise, the term petrol is used in many countries for petroleum.
Gasoline is a mixture of various alkanes, cycloalkanes, with traces of aromatics, with the most important component being 2,2,4-trimethylpentane, which gives the octane rating of the gasoline. The exact composition of gasoline varies, depending on the grade, country and various additives added. The most common additives are antiknock additives, fuel stabilizers, surfactants. It is useful as a non-polar solvent in various organic extractions.
Gasoline burns when ignited in open air, releasing carbon dioxide and water vapors, as well as lots of heat. The combustion of octane, its main component, follows this reaction:
- 2 C8H18 + 25 O2 → 16 CO2 + 18 H2O
Gasoline has a specific energy of 44.4 MJ/kg.
Gasoline is a colorless viscous flammable liquid, with a characteristic petroleum odor. The density of gasoline varies between 0.71–0.77 kg/L, depending on the type. The boiling point of unleaded gasoline is between 35-225 °C, depending on the composition and its melting point is around -57 °C. The flash point of gasoline is -30 °C. It is insoluble in water (0.307 g/L at 20 °C), but miscible with many other organic solvents.
Gasoline is available in gas stations. Some places do not allow individuals to fill jerrycans directly from the pump, usually due to safety concerns. Always ask the gas station personnel if you're allowed to put gas in a jerrycan.
Gasoline is best purchased than made, despite what some might think.
However various methods of producing biogasoline from algae and other biomass have been developed, to produce "green" fuels a.k.a. carbon-neutral.
- Fuel for thermal motors
- Solvent for organic extractions
- Make napalm
Gasoline is extremely flammable and any electric spark, such as an static discharge will cause ignition. Air-fuel mixtures are highly flammable and explosive. Gasoline fires release large amounts of soot and carbon monoxide which are toxic when inhaled. As gasoline is lighter than water and does not mix, gasoline fires are difficult to extinguish. Class B fire extinguishers can be used to put out gasoline fires.
Gasoline vapors are considered hazardous to health. Contact with skin, eye or mouth must be avoided. Ingested gasoline will lead to severe diarrhea. The National Institute for Occupational Safety and Health (NIOSH) has designated gasoline as a carcinogen.
Gasoline should be stored in closed bottles, or better in an airtight container, in a cool, well-ventilated area, away from any heat, fire or spark sources.
Gasoline is generally stable for six months if stored properly but it will slowly break down over time due to the separation of its components. Gasoline stored for a year will still be good to use, but the effects of long term storage will become more noticeable with each passing month.
Gasoline can be burned in open air, though this will release soot and various VOCs, and gasoline smoke has a well known characteristic odor.