Qualifications Scotland (SQA) Advanced Higher Chemistry Past Papers 2026

Structured + extended-response

Duration: 3 hours

Researched investigation

Duration: Coursework — externally assessed

Colour in transition metal complexes — d-d transitions versus HOMO-LUMO versus emission

All three reports flag this confusion. In 2023, markers noted that HOMO-LUMO transitions were frequently offered for transition metal colour, and emission of light was incorrectly cited for both organic and inorganic coloured compounds. The 2025 report showed only some candidates could correctly explain colour differences between two complexes (question 5, Section 1).

Question Paper Section 1, Question Paper Section 2

NMR spectroscopy — interpreting spectra and drawing correct structural formulae

In 2024, most candidates could not interpret an NMR spectrum to draw a correct ester structure (Q6c). Most also could not relate restricted rotation around a C=C double bond to different hydrogen environments (Q6b(ii)). Candidates correctly named the type of radiation used for NMR in 2025 (Q21) but struggled to apply the interpretation.

Question Paper Section 2

Researching chemistry — exact procedural steps for listed techniques

Approximately 24 marks per paper assess researching chemistry. All three course reports identify this as a persistently low-scoring area. Specific failures include: drying precipitate to constant mass (2023), solvent extraction steps (2025), gravimetric analysis steps (2025), and recrystallisation (2024 Q5).

Question Paper Section 2

Stereochemistry — optical isomers, chiral centres, racemic mixtures, and geometric isomers

In 2023, few candidates correctly drew cyclic geometric isomers (Q6c) and few explained how geometric isomers arise in a ring structure. In 2024, many could not identify that a compound was a racemic mixture rather than an achiral molecule (Q1b(ii)). In 2025, most candidates gave incomplete answers about optical isomers and plane-polarised light (Q1c).

Question Paper Section 1, Question Paper Section 2

Equilibrium calculations — determining equilibrium concentrations from initial values

In 2023, few candidates could correctly calculate equilibrium concentrations of H₂ or HI (Q6a(ii)); the most common error was using initial concentrations instead of equilibrium concentrations. Equilibrium-related questions also appeared in the 2024 difficult areas list. Candidates who understand the ICE table method (Initial–Change–Equilibrium) perform significantly better.

Question Paper Section 2

Organic synthesis — multi-step routes with reagents, conditions, and intermediates

In 2024 Q12(d), most candidates could not access more than one of the 3 available marks. Giving only reaction names without reagents or intermediates was the primary failure. In 2025, many candidates drew incorrect ester structures in synthesis questions (Q11a(iii)) and could not correctly apply the aldol reaction to produce a product with a branched structure.

Question Paper Section 2

Electrochemistry and redox — identifying reaction types and oxidation states

In 2025, few candidates identified that gold was being reduced in a displacement reaction (Q10b(i)); many incorrectly gave 'precipitation' as the answer despite it being stated in the question. In 2023, some candidates could determine the oxidation state of chlorine in ClO₄ (Q1a(iii)(A)) but difficulty with complex oxidation state calculations was evident throughout Section 1.

Question Paper Section 1, Question Paper Section 2

Project — risk assessment and evaluative statements with directional effect on results

In both 2024 and 2025, the project risk assessment was the most challenging criterion. Many candidates gave hazards or precautions inappropriate for the concentrations or states used. In 2025, candidates additionally missed flammability of indicators and exaggerated hazards for dilute solutions. Evaluation marks for statements with justification were also low — effect on results was consistently omitted.

Project