Subject Enrichment

Some Vocabulary – Organic Chemistry

Achiral –lacking handedness – a molecules is achiral if it is superimposable on its mirror image.

Addition reaction – the reaction wheretwo reactants combine to form a single new product – typically the addition of a halogen, hydrogen, HCl to a double bond.

Aromatic – a class of compounds that contain a benzene-like six-membered ring with three apparent double bonds.

Carbocation – a carbon cation or a carbon which makes three covelent bonds and has only six valence electrons in outer energy level. Has a trigonal planar molecular geometry.

Chiral – Handed.  A molecule that is not superimposable on its mirror image.

Cis-trans isomers (geometric isomers) – stereoisomers (same connection of atoms) that differ in their arrangement in

space about a double bond or ring.

Dehydration reaction – elimination of water from an alcohol to form an alkene.

Electrophile – an electron-poor molecule or anion that can accept an electron pair from an electron-rich molecule or  cation.

Enantiomers – stereoisomers (same connection of atoms) whose mirror images are non-superimposable.

Functional  group – an atom or group of atoms that is part of a larger molecule and has a characteristic chemical  reactivity.

Mechanism – a complete step-by-step description of how a reaction happens.  The movement of a pair of electrons as the  reaction occurs, is represeted by the complete arrows.

Nylon – a polymer with many amide linkages prepared by the reaction between a diacid and a diamine.

Nucleophile – an electron-rich molecule or anion that can donate an electron pair to an electron-poor molecule or cation.

Nucleophilic substitution reaction – a substitution reaction in which one nucleophile replaces another.

Optical activity – the ability of a molecule in solution to rotate plane-polarized light.

Plane-polarized light – ordinary light that its electric vectors in a single plane rather than in random planes.

Polyester – a polymer with many ester linkages prepared by the reaction between a diacid and a dialcohol.

Racemic mixture – a 50:50 mixture of two enantiomers of a chiral substances – shows no optical activity.

Free Radical – a highly reactive neutral atom or molecule which has an odd number of electrons.

Resonance forms – representations of a molecule that differ only in where the bonding electrons are placed.

Stereochemistry – the branch of chemistry concerned with the three dimensional arrangement of atoms in molecules.

Structural isomers –molecules with the same molecular formula but whose atoms are connected by covalent bonds in a different order.