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Carbon compounds and fuels and feedstocks Typeit
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Alkanes are saturated , compounds that contain only hydrogen and carbon atoms. They are part of a homologous series with hydrogen atoms for every n carbon atoms, and whose first four members are methane, ethane, propane and .
is a finite resource made from the remains of plankton, and consisting of a mixture of compounds, most of which are alkanes. These compounds can be separated in a tower by the process of . They are fed into the heated bottom of the tower and evaporated, then to a liquid at different heights of the tower, which are at different , depending on the size of the molecules.
Size also determines the properties of compounds, with smaller compounds better suited as fuels due to their boiling points, plus the fact that they are generally more volatile and , so burn easily. On the other hand, larger molecules tend to be more , making them thick and sticky.
When large alkanes are cracked, smaller alkanes and are produced. These have the general formula CnH2n, give a positive reaction with , turning it from orange to colourless, and are often used to make , long-chained compounds made up of repeating units. Cracking can be in one of two forms: catalytic cracking, which uses a hot catalyst, or cracking, which uses the power of boiling water and high temperatures. When compounds containing only hydrogen and carbon undergo complete combustion, they form carbon dioxide and .