3.3.1 Introduction to Organic Chemistry

Empirical formula

the simplest whole number ratio of atoms of each element in a compound

Molecular formula

a formula that tells us the actual numbers of atoms of each different element that make up a molecule of a compound

General formula

algebraic formula that can describe any member of a family of compounds

Structural formula

shows the atoms carbon by carbon, with the attached hydrogens and functional groups

Displayed formula

the formula of a compound drawn out so that each atom and each bond is shown

Skeletal formula

a simplified organic formula which only shows the carbon skeleton and associated functional groups

Homologous series

a family of compounds that have:

• same functional group

• same general formula

• consecutive members of homologous series differ by -CH₂-

• similar chemical properties

• different physical properties (e.g. m.p, b.p, solubility)

Isomers

molecules that have the same molecular formula but whose atoms are arranged differently

Structural isomerism

same molecular formula but different structural formulae

Stereoisomerism

two (or more) compounds have the same structural formula but they differ in the arrangement of the bonds in space

E/Z isomerism

a type of stereoisomerism that is caused by the restricted rotation about a carbon-carbon double bond. Each of the carbon atoms must have two different groups attached

E-isomer

a stereoisomer of an alkene that has the two highest priority groups on opposite sides of the carbon-carbon double bond

Z-isomer

a stereoisomer of an alkene that has the two highest priority groups on the same side of the carbon-carbon double bond

Free radical

a chemical species with an unpaired electron - usually highly reactive

addition reaction

reaction where a molecule joins to an unsaturated molecule to produce a saturated molecule

aliphatic

organic compounds containing C chains and branches

aromatic

organic compounds containing one or more benzene rings

carbocation

a positive ion with the positive charge on a C atom

cyclic

organic compounds containing C rings (not aromatic rings)

dehydration

elimination of water

dehydrogenation

elimination of hydrogen

electrophile

lone pair acceptor

elimination reaction

reaction where a molecule is lost from a saturated molecule to form an unsaturated molecule

functional group

the atom or group of atoms that is responsible for most of the chemical reactions of a molecule

hydration

addition of water

hydrocarbon

molecule containing hydrogen and carbon only

hydrogenation

addition of hydrogen

hydrolysis

a reaction involving the breaking of bonds due to reaction with water

nucleophile

lone pair donor

organic chemistry

study of compounds containing carbon

saturated

molecule containing no double bonds

geometric isomers

type of stereoisomerism: molecules which have different arrangement of groups around C-C double bond

optical isomers

type of stereoisomerism: molecules which are non-superimposable mirror images

chain isomers

type of structural isomerism: structural isomers that differ by having a different carbon chain

position isomers

type of structural isomerism: structural isomers that differ by having the functional group in a different position

functional group isomers

type of structural isomerism: structural isomers that differ by having a different functional group

substation reaction

reaction where an atom/group replaces another atom/group

unsaturated

molecule containing double bond(s)