Organic Chemistry: Isomers and Reactions

Vocabulary practice covering organic isomers, heating methods, and various types of organic reactions including substitution, addition, elimination, and esterification.

Isomers

Compounds which have the same molecular formula but different structural formulas.

Chain isomers

Isomers that have different structures due to branching or side chains.

Positional isomers

Isomers with different positions of the same functional group or alkyl substituent on the parent chain.

Functional isomers

Isomers that have the same molecular formula but result in different functional groups.

Water bath

Used for gentle heating of organic reaction mixtures because many organic compounds are flammable.

Heating under reflux

A process where a condenser is attached to the reaction vessel so that any vapours formed during a reaction condense and run back into the reaction vessel.

Combustion (Oxidation) reactions

Exothermic reactions where alkanes, alkenes, or alcohols react with excess oxygen to produce carbon dioxide ($CO_2$) and water ($H_2O$).

Substitution reaction

A reaction occurring in saturated compounds where an exchange of atoms in the reactants takes place.

Halogenation (Substitution)

A reaction where an alkane reacts with a halogen to form a haloalkane, requiring heat or UV light.

Hydrolysis

The reaction of a haloalkane heated under reflux with a dilute base (dilute aqueous alkali solution) to form an alcohol.

Addition reactions

Reactions where a double bond is broken and atoms are added onto a molecule, occurring with unsaturated compounds (alkenes).

Hydrogenation

An addition reaction where hydrogen ($H_2$) is added to an alkene using a platinum ($Pt$), Nickel ($Ni$), or palladium ($Pd$) catalyst.

Bromine test

A test for saturation where bromine water rapidly decolourises when added to an alkene as the double bonds are broken.

Hydrohalogenation

An addition reaction where a hydrogen halide ($HF$, $HCl$, $HBr$, or $HI$) is added to an alkene in the absence of water.

Hydration

An addition reaction where water ($H_2O$) is added to an alkene in the presence of steam and a phosphoric acid ($H_3PO_4$) catalyst.

Elimination reactions

Reactions where atoms or molecular fragments are removed from adjacent atoms to form an alkene; the opposite of addition.

Dehydrohalogenation

The elimination of a hydrogen halide ($HX$) from a haloalkane using a solution of hot concentrated $NaOH$ or $KOH$ dissolved in ethanol without water.

Dehydration

The elimination of water from an alcohol by heating with excess concentrated sulfuric acid ($H_2SO_4$) or phosphoric acid ($H_3PO_4$) as a catalyst.

Cracking of hydrocarbons

The process of breaking large alkane molecules into smaller, more useful molecules, specifically a smaller alkane and one or more small alkenes.

Thermal cracking

A type of cracking that takes place under high pressures and temperatures without a catalyst.

Catalytic cracking

A type of cracking that takes place at lower temperatures and pressures in the presence of a catalyst.

Esterification

A condensation reaction between an alcohol and a carboxylic acid, heated with concentrated sulfuric acid ($H_2SO_4$) as a catalyst and dehydrating agent.