igcse chemistry - organic

reactions of alchohol

1. complete combustion: alchohol + O² = CO² + H²O

2. Oxidises to produce carboxylic acid

3. Oxidising agent: when ethanol is heated with potassium dichromate with sulfuric acid [O], it produces ethanoic acid and water (the potassium dichromate turns from orange to green

hydration of ethene

ethene + water = ethanol

• phosphoric acid is used as a catalyst

• must be steamed at a high temp and pressure

strengths and weaknesses of hydration of ethene

• fast reaction

• continuous

• ethene is non renewable

• high energy costs for high pressure

fermentation

• extract sugar from crops

• add yeast to glucose (enzymes used as a catalyst)

• occurs in 20-40*C, CO² is released, batch process

advantages and disadvantages of fermentation

• cheap equipment needed as it is a batch process

• sugars, renewable source

• very slow

• impure, needs further processing which takes more time and money

what do carboxylic acids and carbonates react to make

• salt, water, and carbon dioxide

• eg: ethanoic acid + potassium carbonate = potassium ethanoate + H²O + CO²

how is ethanol and ethanoic acid made

1. A mixture of ethanoic acid, ethanol and concentrated sulfuric acid is gently heated by either a water bath or an electric heater

2. The ester is then distilled off as soon as it is formed and collected in a separate beaker by condensation

3. As esters have low boiling points, they are the first to evaporate from the reaction mixture. Removing them from the mixture by distillation prevents the reverse reaction from occurring