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==Key Stage 4==
===Meaning===
[[Alkene]]s are [[hydrocarbon]] [[compound]]s with one [[Double Bond|double bond]] and the [[General Formula (Chemistry)|general formula]]; C<sub>n</sub>H<sub>2n</sub>
===About Alkenes===
: The [[Functional Group|functional group]] of the [[Alkene]]s is the [[Double Bond|double bonds]] between the [[Carbon]] [[atom]]s.
: [[Alkene]]s are long chains of [[Carbon]] [[atom]]s [[Covalent Bond|covalently bonded]] together with [[Double Bond|double]] and [[Single Bond|single bonds]] and [[Hydrogen]] [[atom]]s taking the remaining [[Chemical Bond|bonds]].
: [[Alkene]]s are referred to as [[Unsaturated Hydrocarbon|unsaturated hydrocarbons]] because the [[Double Bond|double bond]] means it is not [[Saturated Hydrocarbon|saturated]] (full) with [[Hydrogen]] [[atom]]s.
: [[Alkene Test|Testing for '''alkenes''']] can be done by adding them to [[Bromine Water]]. If the [[Bromine Water]] turns from orange to colourless, then an [[alkene]] is present. During this test the [[Bromine]] [[Chemical Reaction|react]]s with the [[alkene]] to form a [[Bromoalkane]].
: [[Ethene]] + [[Bromine]] → [[Dibromoethane]]
<math>C_2H_4 + Br_2 → C_2H_4Br_2</math>
===Examples===
{| class="wikitable"
|-
| style="height:20px; width:200px75px; text-align:center;" || style="height:20px; width:200px150px; text-align:center;" |'''Ethene'''| style="height:20px; width:200px150px; text-align:center;" |'''Propene| style="height:20px; width:200px150px; text-align:center;" |'''But-1-ene'''| style="height:20px; width:200px150px; text-align:center;" |'''But-2-ene'''
|-
| style="height:20px; width:200px75px; text-align:center;" |[[Chemical Formula]] (C<sub>n</sub>H<sub>2n</sub>)| style="height:20px; width:200px150px; text-align:center;" |C<sub>2</sub>H<sub>4</sub>| style="height:20px; width:200px150px; text-align:center;" |C<sub>3</sub>H<sub>6</sub>| style="height:20px; width:200px150px; text-align:center;" |C<sub>4</sub>H<sub>8</sub>| style="height:20px; width:200px150px; text-align:center;" |C<sub>4</sub>H<sub>8</sub>
|-
| style="height:20px; width:200px75px; text-align:center;" |[[Structural Formula]]| style="height:20px; width:200px150px; text-align:center;" |CH<sub>2</sub>CH<sub>2</sub>| style="height:20px; width:200px150px; text-align:center;" |CH<sub>2</sub>CHCH<sub>3</sub>| style="height:20px; width:200px150px; text-align:center;" |CH<sub>2</sub>CHCH<sub>2</sub>CH<sub>3</sub>| style="height:20px; width:200px150px; text-align:center;" |CH<sub>3</sub>CHCHCH<sub>3</sub>
|-
| style="height:20px; width:200px75px; text-align:center;" |[[Structural Diagram]]
|[[File:StructuralDiagramEthene.png|center|50px]]
|[[File:StructuralDiagramPropene.png|center|100px125px]]
|[[File:StructuralDiagramBut-1-ene.png|center|150px]]
|[[File:StructuralDiagramBut-2-ene.png|center|150px]]
|-
| style="height:20px; width:200px75px; text-align:center;" |[[Ball and Stick Model]]|[[File:BallandStickEthene.png|center|50px100px]]|[[File:BallandStickPropene.png|center|100px125px]]
|[[File:BallandStickBut-1-ene.png|center|150px]]
|[[File:BallandStickBut-2-ene.png|center|150px]]
|}
===Reactions of Alkenes===
====Combustion====
During [[combustion]] of [[alkene]]s the [[Carbon]] and [[Hydrogen]] [[atom]]s are [[oxidised]] to produce [[Carbon Dioxide]] and [[Water]].
=====Complete Combustion=====
[[Complete Combustion|Complete combustion]] occurs when there is enough [[Oxygen]] to completely [[Oxidise]] all of the [[atom]]s in the [[alkene]].
In the [[Complete Combustion|complete combustion]] of [[alkene]]s the only [[product]]s are [[Carbon Dioxide]] and [[Water]].
: [[Ethene]] + [[Oxygen]] → [[Carbon Dioxide]] + [[Water]]
: C<sub>2</sub>H<sub>4</sub> + 3O<sub>2</sub> → 2CO<sub>2</sub> + 2H<sub>2</sub>O
: [[Propene]] + [[Oxygen]] → [[Carbon Dioxide]] + [[Water]]
: 2C<sub>3</sub>H<sub>6</sub> + 9O<sub>2</sub> → 6CO<sub>2</sub> + 6H<sub>2</sub>O
: [[Butene]] + [[Oxygen]] → [[Carbon Dioxide]] + [[Water]]
: C<sub>4</sub>H<sub>8</sub> + 6O<sub>2</sub> → 4CO<sub>2</sub> + 4H<sub>2</sub>O
=====Incomplete Combustion=====
[[Incomplete Combustion|Incomplete combustion]] occurs when there is not enough [[Oxygen]] to [[Oxidise]] all of the [[atom]]s in the [[alkene]].
During [[Incomplete Combustion|incomplete combustion]] of [[alkene]]s the [[product]]s may include [[Carbon]] ([[soot]]) and [[Carbon Monoxide]].
: [[Ethene]] + [[Oxygen]] → [[Soot]] + [[Water]]
: C<sub>2</sub>H<sub>4</sub> + O<sub>2</sub> → 2C + 2H<sub>2</sub>O
: [[Ethene]] + [[Oxygen]] → [[Carbon Monoxide]] + [[Water]]
: C<sub>2</sub>H<sub>4</sub> + 2O<sub>2</sub> → 2CO + 2H<sub>2</sub>O
: [[Ethene]] + [[Oxygen]] → [[Soot]] + [[Carbon Monoxide]] + [[Water]]
: 2C<sub>2</sub>H<sub>4</sub> + 3O<sub>2</sub> → 2C + 2CO + 4H<sub>2</sub>O
====Reaction with Halogens====
When [[halogen]]s are added to [[alkene]]s the [[Double Bond|double bond]] in the [[alkene]]s breaks and the [[halogen]]s [[bond]] in its place.
: [[Ethene]] + [[Chlorine]] → Dichloroethane
: C<sub>2</sub>H<sub>4</sub> + Cl<sub>2</sub> → C<sub>2</sub>H<sub>4</sub>Cl<sub>2</sub>
: [[Propene]] + [[Bromine]] → Dibromopropane
: C<sub>3</sub>H<sub>6</sub> + Br<sub>2</sub> → C<sub>3</sub>H<sub>6</sub>Br<sub>2</sub>
: [[Butene]] + [[Iodine]] → Diiodobutane
: C<sub>4</sub>H<sub>8</sub> + I<sub>2</sub> → C<sub>4</sub>H<sub>8</sub>I<sub>2</sub>
====Reaction with Hydrogen====
[[Alkene]]s can be [[Saturated Hydrocarbon|saturated]] with extra [[Hydrogen]] using a [[catalyst]].
: [[Ethene]] + [[Hydrogen]] → [[Ethane]]
: C<sub>2</sub>H<sub>4</sub> + H<sub>2</sub> → C<sub>2</sub>H<sub>6</sub>
: [[Propene]] + [[Hydrogen]] → [[Propane]]
: C<sub>3</sub>H<sub>6</sub> + H<sub>2</sub> → C<sub>3</sub>H<sub>8</sub>
: [[Butene]] + [[Hydrogen]] → [[Butane]]
: C<sub>4</sub>H<sub>8</sub> + H<sub>2</sub> → C<sub>4</sub>H<sub>10</sub>
====Reaction with Steam====
[[Alkene]]s can [[Chemical Reaction|react]] with [[steam]] to [[product|produce]] [[alcohol]]s using a [[catalyst]].
: [[Ethene]] + [[Steam]] ⇌ [[Ethanol]]
: C<sub>2</sub>H<sub>4</sub>(g) + H<sub>2</sub>O(g) ⇌ C<sub>2</sub>H<sub>5</sub>OH(l)
: [[Propene]] + [[Steam]] ⇌ [[Propanol]]
: C<sub>3</sub>H<sub>6</sub>(g) + H<sub>2</sub>O(g) ⇌ C<sub>3</sub>H<sub>7</sub>OH(l)
: [[Butene]] + [[Steam]] ⇌ [[Butanol]]
: C<sub>4</sub>H<sub>8</sub>(g) + H<sub>2</sub>O(g) ⇌ C<sub>4</sub>H<sub>9</sub>OH(l)
===References===
====AQA====
:[https://www.amazon.co.uk/gp/product/1782945598/ref=as_li_tl?ie=UTF8&camp=1634&creative=6738&creativeASIN=1782945598&linkCode=as2&tag=nrjc-21&linkId=ad276ad49df77ab4b40ab4fd0fe09667 ''Alkenes, page 149, GCSE Combined Science; The Revision Guide, CGP, AQA'']
:[https://www.amazon.co.uk/gp/product/1782945571/ref=as_li_tl?ie=UTF8&camp=1634&creative=6738&creativeASIN=1782945571&linkCode=as2&tag=nrjc-21&linkId=9e29fad914244909903e5e93f8a01d38 ''Alkenes, page 77-80, GCSE Chemistry; The Revision Guide, CGP, AQA'']
:[https://www.amazon.co.uk/gp/product/1471851362/ref=as_li_tl?ie=UTF8&camp=1634&creative=6738&creativeASIN=1471851362&linkCode=as2&tag=nrjc-21&linkId=7d78d70a2044ee9982dae010c94af92a ''Alkenes, pages 147, 148, GCSE Combined Science Trilogy 2, Hodder, AQA'']
:[https://www.amazon.co.uk/gp/product/0198359381/ref=as_li_tl?ie=UTF8&camp=1634&creative=6738&creativeASIN=0198359381&linkCode=as2&tag=nrjc-21&linkId=47c8d1ae58d8b3a5e2094cd447154558 ''Alkenes, pages 154-155, 158-159, 168, GCSE Chemistry; Third Edition, Oxford University Press, AQA'']
:[https://www.amazon.co.uk/gp/product/1471851346/ref=as_li_tl?ie=UTF8&camp=1634&creative=6738&creativeASIN=1471851346&linkCode=as2&tag=nrjc-21&linkId=3ac654f4b0da781c49c855a1af4c92ea ''Alkenes, pages 177-8, GCSE Chemistry, Hodder, AQA'']
:[https://www.amazon.co.uk/gp/product/178294639X/ref=as_li_tl?ie=UTF8&camp=1634&creative=6738&creativeASIN=178294639X&linkCode=as2&tag=nrjc-21&linkId=51599bb45a2bfaf7c1b6a978b2ca2616 ''Alkenes, pages 189, 195, GCSE Combined Science Trilogy; Chemistry, CGP, AQA'']
:[https://www.amazon.co.uk/gp/product/1782945962/ref=as_li_tl?ie=UTF8&camp=1634&creative=6738&creativeASIN=1782945962&linkCode=as2&tag=nrjc-21&linkId=476bb5c8d1dfb5c08ac81b6d4d1c98d8 ''Alkenes, pages 227, 230-237, GCSE Chemistry, CGP, AQA'']
:[https://www.amazon.co.uk/gp/product/1471851346/ref=as_li_tl?ie=UTF8&camp=1634&creative=6738&creativeASIN=1471851346&linkCode=as2&tag=nrjc-21&linkId=3ac654f4b0da781c49c855a1af4c92ea ''Alkenes; formation in cracking reaction, page 176, GCSE Chemistry, Hodder, AQA'']
:[https://www.amazon.co.uk/gp/product/1471851346/ref=as_li_tl?ie=UTF8&camp=1634&creative=6738&creativeASIN=1471851346&linkCode=as2&tag=nrjc-21&linkId=3ac654f4b0da781c49c855a1af4c92ea ''Alkenes; reactions of, pages 178-80, GCSE Chemistry, Hodder, AQA'']
====Edexcel====
:[https://www.amazon.co.uk/gp/product/1292120193/ref=as_li_tl?ie=UTF8&camp=1634&creative=6738&creativeASIN=1292120193&linkCode=as2&tag=nrjc-21&linkId=572df39392fb4200db8391d98ae6314e ''Alkenes, page 275, GCSE Combined Science, Pearson Edexcel '']
:[https://www.amazon.co.uk/gp/product/1782945725/ref=as_li_tl?ie=UTF8&camp=1634&creative=6738&creativeASIN=1782945725&linkCode=as2&tag=nrjc-21&linkId=694be7494de75af3349537d34e13f7f0 ''Alkenes, page 88, 90, 98, 99, GCSE Chemistry; The Revision Guide, CGP, Edexcel '']
:[https://www.amazon.co.uk/gp/product/1782945741/ref=as_li_tl?ie=UTF8&camp=1634&creative=6738&creativeASIN=1782945741&linkCode=as2&tag=nrjc-21&linkId=30da4f2178da182547b62a7329d13b57 ''Alkenes, pages 138, 140, GCSE Combined Science; The Revision Guide, CGP, Edexcel '']
:[https://www.amazon.co.uk/gp/product/1292120215/ref=as_li_tl?ie=UTF8&camp=1634&creative=6738&creativeASIN=1292120215&linkCode=as2&tag=nrjc-21&linkId=8f96ddb76196848bafdb124354e4cf77 ''Alkenes, pages 161, 173, GCSE Chemistry, Pearson, Edexcel '']
:[https://www.amazon.co.uk/gp/product/1782948147/ref=as_li_tl?ie=UTF8&camp=1634&creative=6738&creativeASIN=1782948147&linkCode=as2&tag=nrjc-21&linkId=f63dcd8345f4e49c717b39a228a36c7c ''Alkenes, pages 256, 262, 263, 285-287, GCSE Chemistry, CGP, Edexcel '']
:[https://www.amazon.co.uk/gp/product/1292120215/ref=as_li_tl?ie=UTF8&camp=1634&creative=6738&creativeASIN=1292120215&linkCode=as2&tag=nrjc-21&linkId=8f96ddb76196848bafdb124354e4cf77 ''Alkenes; reactions, pages 174-175, GCSE Chemistry, Pearson, Edexcel '']
====OCR====
:[https://www.amazon.co.uk/gp/product/1782945695/ref=as_li_tl?ie=UTF8&camp=1634&creative=6738&creativeASIN=1782945695&linkCode=as2&tag=nrjc-21&linkId=ceafcc80bcad6b6754ee97a0c7ceea53 ''Alkenes, page 143, Gateway GCSE Combined Science; The Revision Guide, CGP, OCR '']
:[https://www.amazon.co.uk/gp/product/0198359829/ref=as_li_tl?ie=UTF8&camp=1634&creative=6738&creativeASIN=0198359829&linkCode=as2&tag=nrjc-21&linkId=90e8d7b4f039d53035238fa0320fe00b ''Alkenes, pages 232-233, 240-241, 242-243, Gateway GCSE Chemistry, Oxford, OCR '']
:[https://www.amazon.co.uk/gp/product/1782945679/ref=as_li_tl?ie=UTF8&camp=1634&creative=6738&creativeASIN=1782945679&linkCode=as2&tag=nrjc-21&linkId=a2db42f7b4bdf10cafaafa3bb9120940 ''Alkenes, pages 88, 90, 94, GCSE Chemistry; The Revision Guide, CGP, OCR Gateway '']