Definitions A level

an asymmetric carbon atom/ a carbon atom bound to 4 different groups. This may also be called a chiral centre.

shows all the bonds between every atom in the compound.

molecules which are non-superimposable mirror images of one another. Enantiomers have different effects on a plane of polarised light.

a type of stereoisomerism that occurs as a result of the presence of a chiral centre in a molecule. Optical isomers have different effects on a plane of polarised light.

​ a mixture containing equal amounts of enantiomers.

​compounds that only differ in their arrangement of atoms in space.

shows the arrangement of atoms in a molecule without the bonds drawn between them. E.g.CH3 ​C​H2​ C​OCH3​.​

a molecule containing the C=O functional group at the end of the molecule. Aldehydes can be distinguished from ketones using Fehling’s solution or Tollens’ reagent. Aldehydes produce a silver mirror with Tollens’ and a red precipitate with Fehling’s solution. Ketones do not react with either of these reagents.

a functional group with a C=O double bond.

used in mechanisms to show the movement of a pair of electrons

a molecule containing an alcohol group (OH) and a nitrile group (C≡N) bound to the same carbon. These can be formed in a nucleophilic addition reaction between a carbonyl and KCN followed by dilute acid (this reaction forms a mixture of enantiomers if an aldehyde or an unsymmetrical ketone is used).

a molecule containing the C=O functional group in the middle of the molecule. Ketones can be distinguished from aldehydes using Fehling’s solution or Tollens’ reagent. Ketones do not react with either of these reagents while aldehydes produce a silver mirror with Tollens’ and a red precipitate with Fehling’s solution.

an electron pair donor.

a reaction in which an electrophilic π bond reacts with a nucleophile, breaking the π bond and forming 2 new σ bonds.

​aldehydes can be oxidised using acidified potassium dichromate to form carboxylic acids.

​ aldehydes can be reduced to primary alcohols in a nucleophilic addition reaction with NaBH4​ ​ in aqueous solution.

ketones can be reduced to secondary alcohols in a nucleophilic addition reaction with NaBH4​ ​ in aqueous solution.

a molecule containing the OH functional group.

a mixture of methyl esters of long-chain carboxylic acids. Biodiesel is produced by reacting vegetable oils with methanol in the presence of a catalyst.

molecules containing the -COOH functional group. Carboxylic acids are weak acids that form CO2​ ​ when reacted with carbonates.

​molecules containing the R-COO-R’ functional group which can be formed when carboxylic acids and alcohols react in the presence of an acid catalyst. Esters of glycerol (propane-1,2,3-triol) naturally occur in vegetable oils and animal fats and these esters can be hydrolysed in alkaline conditions to produce soaps and glycerol. Esters can be used to create solvents, plasticisers, perfumes and food flavourings.

a piece of apparatus used to determine the melting point of a sample. The recorded melting point range is compared with known values to determine whether the sample is pure.

​under acidic conditions, esters will be hydrolysed to form alcohols and carboxylic acids. Under alkaline conditions, esters will be hydrolysed to form alcohols and carboxylate salts.

an electron pair donor