Propane, butane, and pentane are members of the alkane homologous series.
Why are they classified as members of the same homologous series?
Their successive members differ by a −CH3−-\text{CH}_3-−CH3− group.
They can all be represented by the same general formula.
They have the same molecular formula.
Their physical properties, such as boiling points, are identical.
83 exam-style questions on OCR GCSE Chemistry Organic chemistry. Each one has a worked solution and a mark scheme showing where the marks go.