Reactions of alkenes and alcohols (chemistry only)

describe alkenes

• The first four ethene, propene butene and pentene

• C2H4, C3H6,C4H8,C510

• Formed during cracking

• Used for chemical feedstock and formation of polymers

• React with oxygen in combustion reactions producing carbon dioxide and water but burn in a smokey yellow flame due to incomplete comustion (both types of alkene combustion release less energy per mole than alkanes)

describe the addition with halogens, water,steam

halogen - Two atoms from the halogen molecules are added across the carbon carbon double bond to form a single bond breaking the double bond

Steam - The alkene react with steam at high temp adnd pressure in the presence of a catalyst to form a alcohols

Hydrogen - two atoms from the hydrogen molecule are added across the carbon carbon double bond.

Why are alkenes unsaturated ?

They have double bonds meaning they have space to add other molecules by breaking the double bonds

What is the functional group of alcohols?

-OH

What is the first four alcohols?

Methanol

ethanol

propanol

Butanol

What is the formation of alcohols?

They are formed from the fermentation of sugars. Its a warm sealed mixture of yeast and a sugar solution

What are uses for alcohols?

• alcoholic drinks

• Perfumes

• All four are used mixed with water so are used in a solvent for substances that dont dissolve in water

How are short alcohols effective ?

They are effective fuels and comust easily burning with a blue flame proudcuing C02 and water

2CH3OH + 3O2 → 2C02 + 4H20

Describe the reaction with alcohols and sodium

They react with sodium to release hydrogen producing a product called Alkoxide. Which if added to water releases a very strong alkaline solution.

Describe oxidation in alcohols

They react with oxidising agents to produce carboxylic acid

Describe how ethanol is produced from sugar solution (3)

Its produced from fermentation. You start by adding yeast in anaerobic conditions.

Describe carboxylic acids

• Functional group is cooh

• First four are methanoic acid, ethanoic acid,Propanoic acid and butanoic acid

• They are formed from the oxidation of alcohols

• Ethanoic acid is used in vinegar

How do carboxylic acids react with alcohols and sodium carbonate

• During the reaction with sodium carbonate they react with bases to form salts

• They react with alcohols to make water an esters.This requires sulfuric acid as a catalyst

What happens when carboxylic acids are placed in water?

• During the reaction with sodium carbonate they react with bases to form salts

• They react with alcohols to make water an esters.This requires sulfuric acid as a catalyst