Welcome to brain Stuff from how stuff Works dot com where smart Happens. Hi Am Marshall Brain with today's question, what is the difference between gasoline, kerosene, diesel fuel and so on? The crude oil pumped out of the ground is a black liquid called petroleum. This liquid contains aliphatic hydrocarbons, or hydrocarbons, composed of nothing but hydrogen and carbon, the
carbon atoms linked together in chains of different links. It turns out that hydrocarbon molecules of different links have different properties and behaviors. For example, a chain with just one carbon atom in it is the lightest chain, known as methane. Meth Sane is a gas so light that it floats like helium. As the chains get longer, they get heavier. The first four chains, methane with one carbon, ethane with two carbons, propane with three carbons, and butane with four
carbons are all gases. The chains and the C five, C six, and C seven range are all very light. Easily vaporized clear liquids called napthas. They are used as solvents. Dry cleaning fluids can be made from these liquids, as well as paint solvents and other quick drying products. The chains from C seven through C eleven are blended together and used for gasoline. All of them vaporize at temperatures below the boiling point of water. That's why if you
spill gasoline on the ground, it evaporates very quickly. Next is kerosene in the C twelve to C fifteen range, followed by diesel fuel and heavier fuel oils like heating oil for houses. Next come the lubricating oils. These oils no longer vay prize in any way at normal temperatures. For example, engine oil can run all day at two
degrees fahrenheit without vaporizing at all. Oils go from very light like three and one oil, through various thicknesses of motor oil, through very thick gear oils, and then semi solid greases. Petroleum jelly falls in there as well. Chains above the C twenty range form solids, starting with paraffin wax, then tar, and finally asphaltic bitumn, which is used to make asphalt roads. All these different substances come from crude oil. The only difference is the length of the carbon chains.
Do you have any ideas or suggestions for this podcast. If so, please send me an email at podcast at how stuff works dot com. For more on this and thousands of other topics, go to how stuff works dot com.