Alkanes
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Alkanes are a type of organic compound, specifically a kind of hydrocarbon. They consist solely of carbon and hydrogen atoms.
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These compounds are categorised by single bonds between their atoms, making them a class of saturated hydrocarbons.
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The general formula for alkanes is CnH2n+2, where ‘n’ refers to the number of carbon atoms.
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They are named according to the number of carbon atoms they have. For instance, methane (1 carbon), ethane (2 carbons), propane (3 carbons), and butane (4 carbons).
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Alkanes are used extensively as fuels, including natural gas, petrol, and diesel fuel. This is largely due to their ability to release significant amounts of energy during combustion.
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These compounds exhibit a trend known as homologous series, which means all member compounds are similar in structure and have a fixed increment in molecular mass.
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They are less reactive than alkenes and alkynes due to the absence of a carbon-carbon double bond or triple bond.
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The physical properties of alkanes such as boiling point, melting point and density increase with the rise in the number of carbon atoms.
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Alkanes are nonpolar molecules, making them insoluble in water but soluble in organic solvents.
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They can undergo reactions such as combustion (burning in oxygen), substitution with halogens, and cracking to form smaller alkanes and alkenes.
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Chain branching in alkanes may cause variations in their properties. For example, branched alkanes have a lower boiling point than unbranched, or straight-chain, alkanes.
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Understanding alkanes and their reactions forms an important base for further organic chemistry topics.