A Level Chemistry CIE: Organic Chemistry (A Level Only) Revision Notes

Comprehensive vocabulary flashcards covering functional groups, nomenclature, reaction terminology, isomerism, and polymerisation topics from A Level Chemistry CIE Section 7 (Organic Chemistry).

Functional group

An atom or group of atoms in an organic molecule that determines its characteristic chemical and physical properties.

Arenes

Aromatic compounds that contain a benzene ring.

Halogenoarenes

Aromatic compounds that contain a halogen bonded to a benzene ring; also known as aryl halides.

Phenols

Aromatic compounds containing a hydroxide group bonded to a benzene ring.

Acyl chlorides

Carboxylic acid derivatives containing a chlorine atom attached to a $C=O$ group, also known as 'acid' chlorides.

Amines

Compounds with the $-NH_2$ (primary), $-NH$ (secondary), or $-N$ (tertiary) group which act as basic compounds due to the lone pair of electrons on the nitrogen.

Amides

Compounds containing an amine ($-NH_2$) group and a carbonyl group ($C=O$), resulting in the $-CONH_2$ group.

Amino Acids

Organic compounds that contain both a basic amino ($-NH_2$) group and an acidic carboxylic acid ($-COOH$) group; they serve as the building blocks of proteins.

Electrophilic substitution

Reactions in which an atom or group of atoms is replaced by an electrophile after an initial attack by the electron-deficient species.

Addition reaction

A reaction where two or more molecules combine to give a single product only.

Elimination reaction

The reverse of an addition reaction, where a small molecule such as $H_2O$ or $HCl$ is removed from an organic molecule.

Stereoisomers

Molecules that have the same structural formula but have the atoms arranged differently in space.

Chiral carbon

A carbon atom that has four different atoms or groups of atoms attached to it; also called a chiral centre.

Enantiomers

Optical isomers that are non-superimposable mirror images of each other.

Racemic mixture

A mixture containing equal amounts of enantiomers in a solution, making it optically inactive.

Stereoselectivity

The preference of a reaction to form one enantiomer over the other.

Friedel-Crafts alkylation

An electrophilic substitution reaction where an alkyl chain is substituted into the benzene ring in the presence of an $AlCl_3$ catalyst.

Electron-withdrawing substituents

Groups that remove electron density from the $\pi$ system making the benzene ring less reactive and directing incoming electrophiles to the $3$ and/or $5$ positions.

Electron-donating substituents

Groups that donate electron density into the $\pi$ system making the benzene ring more reactive and directing incoming electrophiles to the $2$, $4$, and/or $6$ positions.

$$pK_a$$

A measure of the acidity of a substance; the smaller the value, the stronger the acid.

Zwitterion

An ion with both a positive ($-NH_3^+$) and a negative ($-COO^-$) charge, characteristic of amino acids depending on $pH$.

Isoelectric point

The $pH$ at which an amino acid exists as a neutral zwitterion.

Peptide bond

The new amide bond formed between two amino acids in a condensation reaction.

Electrophoresis

An analytical technique used to separate ions, such as amino acids, by placing them in an electrical field.

Condensation polymerisation

A reaction used to make polyesters and polyamides where a small molecule, typically $H_2O$ or $HCl$, is lost when monomers join.

Kevlar

A strong and flexible polymer material with fire-resistance properties, made from $1,4\text{-diaminobenzene}$ and $benzene\text{-}1,4\text{-dicarboxylic acid}$.

Photodegradation

The breakdown of polymers using energy absorbed from the Electromagnetic Spectrum, specifically Ultraviolet (UV) light.

Azo compounds

Organic compounds characterized by an $R_1-N=N-R_2$ group, often used as dyes and formed through coupling reactions.