Ethene, C2H4, is the simplest alkene. Its two carbon atoms are joined by a double

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Ethene, C2H4, is the simplest alkene. Its two
carbon atoms are joined by a double covalent
bond.
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The carboncarbon double bond is planar.
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It has bond angles of approximately 120o.
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To name an alkene you need to know the number of
carbon atoms it contains.
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This gives the first part of the alkene's name.
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An alkene is named by adding -ene to the prefix
given by its number of carbon atoms.
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The number of hydrogen atoms in an alkene is
twice its number of carbon atoms.
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The number of hydrogen atoms in an alkene is
twice its number of carbon atoms.
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The number of hydrogen atoms in an alkene is
twice its number of carbon atoms.
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The number of hydrogen atoms in an alkene is
twice its number of carbon atoms.
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The number of hydrogen atoms in an alkene is
twice its number of carbon atoms.
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It helps to know the prefixes given by the number
of carbon atoms and the general formula.
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The molecular formula shows the number of atoms
of each element in ethene.
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The structural formula shows how the atoms are
bonded together in ethene.
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The displayed formula shows all the atoms and all
the bonds in ethene.
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And the same information for propene.
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The double bond can be in more than one position
in butene, so the carbon atoms are numbered.
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The double bond can be in more than one position
in butene, so the carbon atoms are numbered.
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We use the lowest number, so this is but-1-ene
rather than but-2-ene.
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Again, we use the lowest number. This is
but-2-ene rather than but-3-ene.
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Is this but-3-ene or but-4-ene?
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In fact its but-1-ene. It is a mirror image of
the top diagram. Always use the lowest possible
number.
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In fact its but-1-ene. It is a mirror image of
the top diagram. Always use the lowest possible
number.
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In fact its but-1-ene. It is a mirror image of
the top diagram. Always use the lowest possible
number.
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Alkenes can have more than one double bond.
Alkenes with two double bonds are called dienes.
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Alkenes can have more than one double bond.
Alkenes with two double bonds are called dienes.
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This has five carbon atoms. We use the lowest
numbers, so this is penta-1,3-diene.
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This is propene with a methyl group attached.
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It is methylpropene.
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Cyclic alkenes like this have cyclo- at the start
of their names.
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This has six carbon atoms. It is cyclohexene.