Review the key concepts, formulae, and examples before starting your quiz.
🔑Concepts
A homologous series is a family of organic compounds that share the same general formula, have the same functional group, and exhibit similar chemical properties.
Members of a homologous series show a gradation in physical properties. For example, as the number of carbon atoms increases, the boiling point increases due to stronger intermolecular forces.
Each successive member of a homologous series differs by a unit and has a relative molecular mass that increases by .
IUPAC Nomenclature follows a specific hierarchy: Stem (number of carbon atoms in the longest chain), Suffix (primary functional group), and Prefix (substituents like halogens or alkyl groups).
Common stems for carbon chains: = meth-, = eth-, = prop-, = but-, = pent-, = hex-.
Functional Groups define the chemical reactivity: Alkanes (single bonds), Alkenes ( double bonds), Alcohols (), Carboxylic Acids (), and Esters ().
Structural Isomers are molecules with the same molecular formula but different structural arrangements, such as chain isomers, position isomers, or functional group isomers.
📐Formulae
💡Examples
Problem 1:
Provide the IUPAC name for the compound with the structural formula .
Solution:
Propan-1-ol
Explanation:
The longest carbon chain contains carbons, giving the stem 'prop-'. All carbon-carbon bonds are single, indicating 'an'. The functional group is a hydroxyl group () attached to the first carbon, providing the suffix '-1-ol'.
Problem 2:
Identify the molecular formula of the fourth member of the alkene homologous series.
Solution:
Explanation:
The alkene series starts with Ethene (). The second member is Propene (), the third is Butene (), and the fourth is Pentene (). Using the general formula , for , we get .
Problem 3:
Draw and name the ester formed by the reaction of ethanol () and propanoic acid ().
Solution:
Ethyl propanoate ()
Explanation:
In esterification, the alcohol provides the alkyl prefix (ethanol ethyl) and the carboxylic acid provides the alkanoate suffix (propanoic acid propanoate).