2.5.4

Introduction to Alkenes

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Alkenes

Alkenes are hydrocarbons with the functional group C=C. This means that alkenes have a carbon-carbon double bond.

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Unsaturated

  • Alkenes are unsaturated hydrocarbons because they contain a double bond between two of their carbon atoms (C=C).
  • This means that an alkene contains two fewer hydrogen atoms than the alkane with the same number of carbon atoms.
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Formula

  • A homologous series is a series of compounds with the same general formula.
    • CnH2n is the general formula for alkenes.
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Reactive

  • Alkenes are more reactive than alkanes.
    • This is because the double bond is of high electron density.

The Four Shortest Alkenes

The four shortest alkenes, in ascending (increasing) size order, are:

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Ethene

  • Ethene has the formula C2H4.
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Propene

  • Propene has the formula C3H6.
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Butene

  • Butene has the formula C4H8.
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Pentene

  • Pentene has the formula C5H10.

Jump to other topics

1Structure - Models of the Particulate of Matter

2Structure - Models of Bonding & Structure

3Structure - Classification of Matter

3.1The Periodic Table: Classification of Elements

3.2Periodic Trends

3.3Group 1 Alkali Metals

3.4Halogens

3.5Noble gases, group 18

3.6Functional Groups: Classification of Organic

3.7Functional Group Chemistry

3.8Alkanes

3.9Alcohols

3.10Halogenoalkanes

4Reactivity - What Drives Chemical Reaction?

5Reactivity - How Much, How Fast & How Far?

6Reactivity - The Mechanisms of Chemical Change

7Measurement, Data Processing & Analysis

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