Organic Reactions
This page covers:
alkenes, alcoholes, carboxylic acids, esters, hydrogenation, homologous series, fermentation,
Key Words
Alkenes - hydrocarbons, they have a double carbon-carbon, C=C, bond in their chain. They are unsaturated.
- The first four alkenes are ethene (two carbon atoms), propene (three carbon atoms), butene (four carbon atoms), pentene (five carbon atoms).
- Alkenes combust completely in a large amount of oxygen to product water and carbon dioxide.
- Alkenes react via additon reactions. The double bond opens up to create a single bond. Alkenes can react with Halogens this way.
- Mix alkenes with steam and them pass it over a catalyst to form alcohols.
Hydrogenation - hydrogen reacts with double-bonded carbons to create a single bond with a catalyst.
Catalyst - a substance that speeds up a reaction without being used up in the reaction itself.
Homologous series - a group of chemicals that react in a similar way, they have the same functional group.
Alcohols
- Contain an -OH functional group.
- They are flammable.
- Their solutions have a neutral pH.
- They react with sodium.
- They can be oxidised.
- Methanol and ethanol are used as solvents.
- Ethanol is used as fuel in spirit burners, it's clean and non-smelly.
- Ethanol is found in alcoholic drinks, it's made by fermentation.
Carboxylic Acids
- Contain -COOH as a functional group.
- React with carbonates to produce a salt, water and carbon dioxide.
- Can dissolve in water. They ionise and release H+ ions making an acidic solution.
Esters
- Contain -COO- as a functional group.
- Formed from alcohol and carboxylic acid with an acid catalyst.
Links for Learning
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Bitesize: Alkanes and alkenes
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Bitesize: Alcohols
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Bitesize: Carboxylic acids and esters
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