Introduction to Organic Chemistry Mind Map (A Level)

A family of compounds with the same functional group and general formula, where each member differs by CH₂.

Molecular, empirical, general, structural, displayed and skeletal formulae.

Same molecular formula, different structural formula: chain, position and functional group isomers.

A type of stereoisomerism caused by restricted rotation around a C=C double bond. Priorities are set by the Cahn-Ingold-Prelog rules: Z when the higher-priority groups are on the same side, E when opposite.

Separated into fractions by fractional distillation, based on boiling point.

Breaks long alkanes into shorter, more useful ones and alkenes. Thermal cracking uses high temperature and pressure; catalytic cracking uses a zeolite catalyst and gives branched and aromatic hydrocarbons.

Complete combustion gives carbon dioxide and water. Incomplete combustion also gives carbon monoxide and soot. Pollutants such as nitrogen oxides and sulfur dioxide are reduced by catalytic converters and flue gas desulfurisation.

Alkane + chlorine in UV light. Initiation forms chlorine radicals; propagation steps keep the chain going; termination joins two radicals.

Nucleophiles such as hydroxide ions, cyanide ions and ammonia attack the slightly positive carbon and replace the halogen.

Set by the C–X bond enthalpy: the C–I bond is the weakest, so iodoalkanes react fastest.

With hydroxide ions in hot ethanol, the hydroxide acts as a base and an alkene forms.

UV light breaks C–Cl bonds in CFCs, releasing chlorine radicals that catalyse the breakdown of ozone.

Electrophiles such as hydrogen bromide, bromine and sulfuric acid add across the double bond, through a carbocation intermediate.

With an unsymmetrical alkene, the more stable carbocation (tertiary over secondary over primary) leads to the major product.

Bromine water turns from orange to colourless.

Alkenes join to form polymers such as poly(ethene) and poly(chloroethene). They are unreactive, which makes disposal a problem.

Hydration of ethene with steam and a phosphoric acid catalyst (fast, continuous, uses a finite resource), or fermentation of glucose by yeast (renewable, slower, impure).

With acidified potassium dichromate, which turns from orange to green:

• Primary: aldehyde (distil it off), then carboxylic acid (heat under reflux)
• Secondary: ketone
• Tertiary: not oxidised

Aldehydes give a silver mirror with Tollens' reagent and a red precipitate with Fehling's solution; ketones do not.

Heating an alcohol with a concentrated acid catalyst removes water, forming an alkene.

• Free-radical substitution (alkanes)
• Nucleophilic substitution (halogenoalkanes)
• Elimination (halogenoalkanes, alcohols)
• Electrophilic addition (alkenes)
• Addition polymerisation (alkenes)

Nucleophiles donate an electron pair and are attracted to positive centres. Electrophiles accept an electron pair and are attracted to areas of high electron density.

Start each arrow at a lone pair or a bond, show the dipole on polar bonds, and draw the intermediate with its charge.