organic chemistry

-long chain molecules are passed over a heated catalyst and are broken down into shorter chain molecules

hydrocarbons with the same molecular formula but different structural formulas

unsaturated hydrocarbons (alkenes) joined together in polymerisation

the joining of 2 molecules with the elimination of a small molecule (usually water)

condensation polymers in which the monomers are joined by ester linkages (COO)

condensation polymers in which the monomers are joined by amide linkages (CONH)

• biodegradable polymers often contain ester/amide links which can be easily broken down by addition of water • non-biodegradable polymers often consist of long chains of C and H atoms which have strong bonding between the atoms, making them resistant to breakdown by microorganisms or enzymes

• alcohol + carboxylic acid -> ester + water - conc sulphuric acid used as catalyst

-branching in alkanes weakens intermolecular forces as they are more compact with less surface area -> lower mp/bp than straight chain molecules with the same Mr

the top of a fractionating column is where the hydrocarbon with the lowest bp fractions off

• bp increases • viscosity increases • flammability decreases • volatility decreases

-polyalkenes no longer contain a C to C double bond because they have been broken to join more monomers