Topic 10 - Organic Chemistry

Homologous series

A family of compounds that differs only by the length of its hydrocarbon chain. Members share a general formula and chemical properties.

Melting/boiling points in a homologous series

increase going down the series or as LDF increases

empirical formula

The simplest ratio of elements in a compound.

molecular formula

The actual number of atoms of each element in a compound.

structural formula

A formula that shows the arrangement of atoms and bonds in a molecule.

condensed formula

A formula that shows the connectivity of atoms in a molecule, but does not show all the bonds.

skeletal formula

A simplified way of representing organic molecules by using lines to represent carbon-carbon bonds and omitting carbon and hydrogen atoms.

Isomers

Compounds with the same molecular formula but different structural formulas.

Saturated compound

have single bonds

Unsaturated compound

have double/triple bonds

Aliphatic compounds

Straight-chain compounds.

Cycloalkanes

Ring structures that contain only single bonds (C-C).

Arenes

Ring structures consisting of alternating double bonds (C=C).

Benzene - Kekule Structures

Radicals

Species with unpaired electrons that are highly reactive.

Alkenes + Hydrogen

product = alkane; heat + nickel catalyst needed

Alkenes + Hydrogen halides

product = halogenoalkanes; no required conditions

Alkenes + Water

product = alcohol; steam + sulphuric acid catalyst

Polymerisation

Under certain conditions, alkene molecules can add to each other to form polymers.

Alcohols as Fuels

Alcohols combust more than alkanes but release less energy.

Oxidation of Alcohol

Alcohols can be oxidized to form aldehydes or carboxylic acids, depending on the conditions and the type of alcohol.

Alcohol Oxidation Agent

Potassium dichromate

Nucleophilic Substitution

A reaction where a nucleophile replaces a leaving group in a molecule. Halogenoalkanes can undergo nucleophilic substitution reactions.

Ester

A compound formed by the reaction of a carboxylic acid and an alcohol.