Organic II - 5.3

alcohols are organic molecules containing -OH functional group

in this method, Ethan gas is mixed with steam under the following conditions 300° C 65 atmosphere pressure Phosphoric acid, catalyst

Crude oil provides the ethene

Makes pure ethanol. Can run continuously

Conditions require lots of energy. Non-renewable raw material used

yeast, provides enzymes 30° C: enzymes optimum temperature. Anaerobic: prevents oxidation

Sugarcane provide provides the glucose

Renewable raw material used Conditions not energy intensive

Makes impure ethanol. Must be done in individual batches

Ethanol tends to combust completely because of the oxygen atom in the –OH group. This results in a non-luminous blue flame

many microorganisms such as bacteria and fungi can use the oxygen in the air to oxidise ethanol into ethanoic acid This can only happen aerobically

When we want to deliberately oxidise ethanol in the lab, we heat it with a mixture of: Potassium dichromate Dilute sulphuric acid As this occurs the orange dichromate irons are turned into green chromium(III) irons This means the reaction is always accomplished by the same colour change: Orange —> green

organic molecules containing -COOH functional group

Vinegar is an aqueous solution of ethanoic acid It forms when ethanol and wine undergoes microbial oxidation. Vinegar has a very sour accurate taste because of the acidity of ethanoic acid

Esters are a family of organic molecules which form when carboxylic acid and an alcohol join together by losing H2O molecule

condensation because of the production of water vapour

• Mix the carboxylic acid and alcohol together. • Add a few drops of concentrated sulphuric acid – this acts as a catalyst for the reaction. • Warm it for a while. • Tip the mixture into sodium carbonate solution. This neutralises the sulphuric acid catalyst which is otherwise really corrosive this reaction produces CO2 so you wait until the fizzing has stopped

A polyester is a polymer made of lots of molecules joined together in a chain by ester groups

Dicarboxylic acid - has –COOH at both ends. Diol – has –OH at both ends

some polyesters are biodegradable which means microbes such as bacteria and fungi can use enzymes to break down the polymer into its monomers and use them as an energy supply