A-Level Chemistry: Organic Chemistry I

Organic chemistry at A-level is a language before it is a subject: isomer types, mechanism names, and the conditions that steer one product over another. This quiz covers the Year 1 organic foundations — the vocabulary and the first four mechanism families.

The isomerism questions map the full taxonomy: chain and functional-group isomerism as the structural branch, E-Z isomerism with both of its requirements (restricted rotation and two different groups on each alkene carbon), and optical isomerism through the exact definition of a chiral centre — four different groups — and its physical signature, the opposite rotation of plane-polarised light by enantiomers.

The mechanism questions cover the canonical four. Free-radical substitution is tested at its initiation step — homolytic fission generating radicals. Nucleophilic substitution of halogenoalkanes carries the topic's key trend question: why hydrolysis accelerates from chloro- to iodoalkanes (the weakening carbon-halogen bond, not electronegativity — the classic trap). The substitution-versus-elimination fork is pinned to its conditions: ethanolic solvent and heat favouring elimination for 2-bromobutane. Electrophilic addition to alkenes brings Markovnikov reasoning through carbocation stability rather than rule-recitation.

Addition polymers close the set — unsaturated monomers producing a saturated backbone, the link between alkene chemistry and materials.

The blind-solver verification pass returned complete agreement across all ten questions. Explanations name each mechanism and its governing factor explicitly, building the precise vocabulary that organic exam answers are marked on. The Organic II and Analysis quizzes in this collection continue the sequence into Year 2.

• Classify structural, E-Z and optical isomerism with exact criteria
• Describe free-radical substitution step by step
• Explain the halogenoalkane reactivity trend via bond enthalpy
• Choose conditions that steer substitution vs elimination
• Apply Markovnikov reasoning through carbocation stability

Aligned to the Year 1 organic core of the DfE A level science subject content: nomenclature and isomerism, alkanes and free-radical substitution, halogenoalkanes, alkenes and addition polymers.