| Method |
Precise Learning Objective |
Linked |
Question / Activity
(Designed for maximum working out) |
Stepping Stones |
Pitstop Check
(Thinking Map) |
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Alkenes are hydrocarbons with a double carbon-carbon bond. |
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What is the structure of an alkene like? Stretch - identify if hydrocarbons are alkanes or alkenes using their structural formulas
Challenge - identify if hydrocarbons are alkanes or alkenes using only their empirical formulas |
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The general formula for the homologous series of alkenes is CnH2n. Recognise substances that are alkenes from their names or from given formulae in these forms. |
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What is the general formula for the homologous series of alkenes? Ask them to deduce the general formula from the starter activity |
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Alkene molecules are unsaturated because they contain two fewer hydrogen atoms than the alkane with the same number of carbon atoms. |
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Why are alkene molecules called unsaturated molecules? Compare the structures of both and remind them of the reaction with chlorine. |
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Students should be able to describe the reactions and conditions for the addition of water alkenes |
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What are the conditions for the addition of water to alkenes? Introduce the concept of specific conditions for addition reactions. |
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Students should be able to describe the reactions and conditions for the addition of halogens to alkenes
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What are the conditions for the addition of halogens to alkenes? |
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The first four members of the homologous series of alkenes are ethene, propene, butene and pentene. |
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What are the names of the first four members of the homologous series of alkenes? Apply Monkeys Eat Peanut Butter to the alkenes |
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Alkene molecules can be represented in the following forms: C3H6 or displayed formula |
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What is the structural and display formula ethene? |
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Students do not need to know the names of individual alkenes other than ethene, propene, butene and pentene. |
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What is the structural and display formula pentene? Draw the structural and display formula for the first five alkenes. |
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Alkenes are hydrocarbons with the functional group C=C. |
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What is the functional group for alkenes? Teach what a functional group is and then ask them to identify the functional groups of alkenes, alcohols and carboxylic acids |
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It is the generality of reactions of functional groups that determine the reactions of organic compounds. |
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What determines the reactions of organic compounds? |
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Alkenes react with oxygen in combustion reactions in the same way as other hydrocarbons, but they tend to burn in air with smoky flames because of incomplete combustion. |
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How does the combustion of alkenes differ in oxygen and in air? |
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Alkenes react with hydrogen, water and the halogens, by the addition of atoms across the carbon-carbon double bond so that the double bond becomes a single carbon-carbon bond. |
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How do alkenes react with hydrogen, water and the halogens? |
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Students should be able to describe the reactions and conditions for the addition of hydrogen to alkenes |
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What are the conditions required for the addition of hydrogen to alkenes? |
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Students should be able to describe the reactions and conditions for the addition of hydrogen to alkenes |
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What are the conditions required for the addition of water to alkenes? |
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Students should be able to draw fully displayed structural formulae of the first four members of the alkenes and the products of their addition reactions with hydrogen, water, chlorine, bromine and iodine. |
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What are the structures of the following products of alkene addition reactions:
1. dibromoethane
2. dichloroethane
3. ethanol
4. ethane Produce a table that summarises the different reactions of alkenes, it should include their reaction with oxygen, with air, addition hydrogen and halogens. The table should include any critical observations and the products formed. |
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