Octane is an alkane with the chemical formula C8H18. As a hydrocarbon, it can be burned as a fuel. This organic molecule is a colourless liquid at room temperature with a characteristic "gasoline" odour.[2] Its principle use is as a component of gasoline, and the performance of this gasoline depends on its octane rating which gets its name from this molecule. Note however, that the concept of octane rating is a little more complicated than just 'how much octane there is in the fuel'. The balanced chemical equation for the complete combustion of octane is:
[math]\ce{2C_8H_{18} + 25(O_2)\leftrightarrow 16(CO_2) + 18(H_2O)}[/math]
Below is a table of some of the basic properties of octane.
Formula | C8H18 |
Molar mass | 114.23 grams/mole |
Energy density | 47.9 MJ/kg [3] |
Melting Point | -57oC[4] |
Boiling Point | 125oC[4] |
As is the case with other hydrocarbons, octane undergoes hydrocarbon combustion, combining with oxygen to form carbon dioxide. The balanced chemical equation for the complete combustion of octane is:
The hydrocarbon combustion reaction releases heat energy and is an example of an exothermic reaction. The reaction also has a negative enthalpy change (ΔH) value.
Semaa Amin, Ethan Boechler, Jordan Hanania, James Jenden, Kailyn Stenhouse, Jason Donev
Last updated: September 27, 2021
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