What does gasoline consist of?

Answer 1

Gasoline is a liquid that can burn smoothly and not detonate and will burn clean and provide some lubrication cushion to the valves and upper piston rings. Also gasoline
must not burn too hot or the metal valves and top of the piston will melt and that is hot!
Gasoline must also be cheap or in capitalistic countries the buyer will buy the most affordable gasoline that delivers the a fore mentioned quality's and not buy the exotic gasoline distilled from something more exotic. So gas starts off with petroleum distillates or the lighter liquids of each oil base. Some oils have a lot of acetone so some acetone is removed, some oils have excessive toluene, benzine, and many ingredients used in paints
and even alcohol can be an ingredient in gasoline. Detergents and fine oils can be added also and many other ingredients. When gasoline has water moisture that is not absorbed into the brew then the engine may buck and skip and loose power. A high power engine can have high compression and need gas that explodes or burns less easy than a lawn mower.

Answer

To explain what gasoline is you need a short lesson in organic chemistry! Chemical compounds that are made of just carbon and hydrogen are called hydrocarbons. All hydrocarbons contain just carbon and hydrogen, but the relative amounts of these elements, and the ways they are arranged in the molecules of each hydrocarbon, affect the properties of the hydrocarbon.

The simplest hydrocarbons are gases. Methane (CH4) is also known as natural gas and is the gas produced when bacteria respire without air being present. Anopther hydrocarbon ethene (C2H4) is a gas used to produce the plastic polythene. Other hydrocarbons include Butane (C4H10) or 'camping gas' - the gas used in cigarette lighters and ethyne (acetylene) (C2H2) used in oxy-acetylene torches for welding.

The more complex hydrocarbon molecules (those with 5 or more Carbon atoms per molecule) are liquids. In gasoline, this liquid consists of a mixture of different hydrocarbons, but the largest constituent of this mixture is octane (C8H16) which can make up 95-98% of unleaded gasolene. Other constituents include heptene (C7H14), heptane (C7H16) and benzene (C6H6) among many others.