Advanced Higher Chemistry: the shorter 2027 exam, the project and practice questions

The Advanced Higher Chemistry exam in 2027

That's 134 marks in all. The figures are from the course specification valid from session 2026 to 2027, and the date from the 2027 timetable. Section 2 lost 10 marks and the paper lost 30 minutes after a survey of learners and teachers. The content and the project haven't changed. The course is worth 32 SCQF credit points.

The project: you investigate a chemistry topic of your own, carry out the experiments, and write a report. The specification expects about 10 to 15 hours of experimental work.

What Advanced Higher Chemistry covers

• Inorganic chemistry: electromagnetic radiation and atomic spectra, atomic orbitals, electronic configurations and the periodic table, and transition metals.
• Physical chemistry: chemical equilibrium (including acids, bases and buffers), reaction feasibility and kinetics.
• Organic chemistry and instrumental analysis: molecular orbitals, synthesis, stereochemistry, finding structures by experiment (including NMR and infrared spectroscopy), and pharmaceutical chemistry.
• Researching chemistry: apparatus, practical skills, stoichiometric calculations and gravimetric and volumetric analysis.

Advanced Higher Chemistry grade boundaries

In 2026, on the old format, out of 160 (the 110-mark paper scaled to 120, plus the project scaled to 40), an A needed 108, a B 90, a C 73 and a D 55. Of the 3,045 candidates, 27.8% got an A (course report 2026). The 2027 total is 134, so those numbers won't carry over. As a guide, the grading system aims for a C at about 50% and an A at about 70%.

Advanced Higher Chemistry practice questions

We wrote these for this guide. Take constants from the data booklet, and show each step.

1. pH of a strong base

Question: find the pH of 0.020 mol l⁻¹ sodium hydroxide at 25 °C. Answer: [OH⁻] = 0.020 mol l⁻¹. From the ionic product of water, [H⁺] = 1 × 10⁻¹⁴ ÷ 0.020 = 5 × 10⁻¹³ mol l⁻¹, so pH = −log(5 × 10⁻¹³) = 12.3. For a base like calcium hydroxide, remember each formula unit gives two OH⁻ ions: in 2026 only some candidates got a question like this right.

2. pH of a weak acid

Question: estimate the pH of 0.10 mol l⁻¹ ethanoic acid, pK_a = 4.76. Answer: pH = ½pK_a − ½log c = 2.38 − ½ × (−1) = 2.88. It's higher than for a strong acid of the same concentration (pH 1), because the weak acid only partly dissociates. Try more in the pH Calculator.

3. Reaction feasibility

Question: for a decomposition, ΔH° = +178 kJ mol⁻¹ and ΔS° = +161 J K⁻¹ mol⁻¹. Above what temperature is it feasible? Answer: it becomes feasible when ΔG° = ΔH° − TΔS° falls to zero, so T = ΔH° ÷ ΔS° = 178 000 ÷ 161 = 1106 K. Convert kJ to J first. Above 1106 K, ΔG° is negative.

4. Rate equations

Question: a reaction has rate = k[P][Q]². What happens to the rate if [Q] doubles, and what is the overall order? Answer: the rate depends on [Q] squared, so doubling [Q] multiplies the rate by 2² = 4. The overall order is 1 + 2 = 3. Practise using a rate equation in our Reaction Kinetics course and press Mark.

5. Energy of light

Question: sodium's yellow line has a wavelength of 589 nm. Find the energy in kJ mol⁻¹. Answer: E = Lhc ÷ λ = 6.02 × 10²³ × 6.63 × 10⁻³⁴ × 3.00 × 10⁸ ÷ 589 × 10⁻⁹ = 203 000 J mol⁻¹, or 203 kJ mol⁻¹. Each line in an emission spectrum comes from electrons dropping between two energy levels, and atoms have many levels, so you see a series of lines.

Common Advanced Higher Chemistry mistakes

From the 2026 course report:

• pH of hydroxides with two OH⁻ ions, such as calcium hydroxide, worked as if they had one.
• Emission spectra: explaining one line but not why there's a series (many energy levels).
• Atomic absorption: saying absorbance relates to concentration without saying how (a calibration graph), or describing how to identify an element instead of measuring it.
• ΔG and ΔG°: few could state the difference, though it's a definition in the course specification. ΔG° is under standard conditions.
• Padding answers with information the question didn't ask for.

Use a daily paper as a short timed prelim

Today's Advanced Higher Chemistry paper covers acids, bases and buffers, rate equations, entropy, transition metals, NMR and spectroscopy, aromatic chemistry, carbonyl compounds, amines and organic synthesis, which are all in the course. It also includes Born Haber cycles, electrode potentials and K_p, which aren't in Advanced Higher Chemistry, and it doesn't cover atomic spectra and orbitals, stereochemistry or pharmaceutical chemistry, or have a multiple-choice section. Use it alongside the official past papers, remembering that papers before 2027 are longer. For prelim dates, see our prelims guide.

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