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Homologous seriesCycloalkanes

The alkanes, alkenes and cycloalkanes are examples of homologous series. A homologous series is a group of chemicals which have similar chemical properties and can be represented by a general formula.

Part of ChemistryNature's chemistry

Cycloalkanes

The third homologous series is the cycloalkanes. Their names all end in 鈥ane and begin with cyclo-, for example cyclopropane. The cycloalkanes have the general formula \({C_n}{H_{2n}}\).

The first four cycloalkanes. Cyclopropane (C3H6) has three carbon atoms arranged in a triangle. Each carbon atom is single bonded to the other two. They are all additionally bonded to two hydrogen atoms each. Cyclobutane (C4H8) has four carbon atoms arranged in a square. Each carbon atom is single bonded to the two on either side of it. They are all additionally bonded to two hydrogen atoms each. Cyclopentane (C5H10) has five carbon atoms arranged in a pentagon. Each carbon atom is single bonded to the two on either side of it. They are all additionally bonded to two hydrogen atoms each. Cyclohexane (C5H10) has six carbon atoms arranged in a hexagon. Each carbon atom is single bonded to the two on either side of it. They are all additionally bonded to two hydrogen atoms each.

Even though they have the same general formula as the alkenes, the cycloalkanes are saturated and contain only single bonds. This means that they do not quickly decolourise bromine solution. Cyloalkanes are isomers of the alkenes.

Many cycloalkanes are used in motor fuel, natural gas, kerosene, diesel and other heavy oils.

General formula, functional group and properties of cycloalkanes.

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