5.4.1

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

1Physical Chemistry

2Physical Chemistry 2 (A2 Only)

3Inorganic Chemistry

4Inorganic Chemistry 2 (A2 Only)

5Organic Chemistry 1

6Organic Chemistry 2 (A2 Only)

6.1Optical Isomerism (A2 Only)

6.2Aldehydes & Ketones (A2 Only)

6.3Carboxylic Acids & Esters (A2 Only)

6.4Aromatic Chemistry (A2 Only)

6.5Amines (A2 Only)

6.6Polymers (A2 Only)

6.7Biological Organic (A2 Only)

6.8Organic Synthesis (A2 Only)

6.9NMR Spectroscopy (A2 Only)

6.10Chromatography (A2 Only)

6.11A-A* (AO3/4) - Organic 2

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