Higher Chemistry: the new single paper for 2027, the assignment and practice

The Higher Chemistry exam in 2027

The exam counts for 80% and the assignment for 20%. Until 2026 there were two papers: Paper 1 (25 multiple-choice marks in 40 minutes) and Paper 2 (95 marks in 2 hours 20 minutes). Qualifications Scotland merged and shortened them after a survey of learners and teachers. The new format is in the course specification valid from session 2026 to 2027; the content is unchanged.

The assignment: you research a topic, carry out an experiment and write a report. The task should take no more than 8 hours, with at most 2 hours to write the report under supervision, and Qualifications Scotland marks it.

What Higher Chemistry covers

• Chemical changes and structure: periodicity, structure and bonding, and oxidising and reducing agents.
• Nature's chemistry: systematic carbon chemistry, alcohols, carboxylic acids and esters, fats and oils, soaps, detergents and emulsions, proteins, oxidation of food, fragrances and skin care.
• Chemistry in society: getting the most from reactants, controlling the rate, chemical energy, equilibria and chemical analysis.
• Researching chemistry: common apparatus, practical techniques and reporting experimental work.

Higher Chemistry grade boundaries

In 2026, on the old format, out of 150 (120 marks over two papers, plus the assignment scaled to 30), an A needed 105, a B 87, a C 70 and a D 52. Of the 9,991 candidates, 32.9% got an A (course report 2026). The 2027 course is out of 125, 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%.

Higher Chemistry practice questions

We wrote these for this guide. Take data from the data booklet where you need it, and set out every calculation.

1. Polar molecules

Question: explain fully why ammonia, NH₃, is a polar molecule. Answer: nitrogen is more electronegative than hydrogen, so each N-H bond is polar, with N slightly negative. The molecule is pyramidal, so the bond dipoles don't cancel and the molecule has a permanent dipole. You need both parts, the polar bonds and the shape, for full marks.

2. Percentage yield

Question: 4.6 g of ethanol (gram formula mass 46 g) reacts with excess ethanoic acid to make ethyl ethanoate (88 g), and 6.6 g is collected. Find the percentage yield. Answer: moles of ethanol = 4.6 ÷ 46 = 0.10 mol, and the ratio is 1 : 1, so the theoretical mass of ester is 0.10 × 88 = 8.8 g. Percentage yield = 6.6 ÷ 8.8 × 100 = 75%.

3. Enthalpy of combustion

Question: burning 0.23 g of ethanol raises the temperature of 100 cm³ of water by 15.0 °C. Calculate the enthalpy of combustion. Answer: E_h = cmΔT = 4.18 × 0.100 × 15.0 = 6.27 kJ. Moles burned = 0.23 ÷ 46 = 0.005 mol. ΔH = −6.27 ÷ 0.005 = −1254 kJ mol⁻¹. The sign is negative because combustion is exothermic.

4. Bond enthalpies

Question: using bond enthalpies of 436 kJ mol⁻¹ (H-H), 243 kJ mol⁻¹ (Cl-Cl) and 432 kJ mol⁻¹ (H-Cl), estimate ΔH for H₂ + Cl₂ → 2HCl. Answer: energy in to break bonds = 436 + 243 = 679 kJ. Energy out when bonds form = 2 × 432 = 864 kJ. ΔH = 679 − 864 = −185 kJ mol⁻¹. Try one in our Chemical Bonding course and press Mark.

5. Equilibria

Question: in N₂(g) + 3H₂(g) ⇌ 2NH₃(g), explain fully why raising the pressure increases the yield of ammonia. Answer: there are 4 moles of gas on the left and 2 on the right. Higher pressure favours the side that takes up less volume, here the right with only 2 moles of gas, so more ammonia forms. The 2026 report found few candidates gave both parts of an answer like this. Explore it in the Rates and Equilibrium simulator.

Common Higher Chemistry mistakes

From the 2026 course report, most lost marks were on "explain fully" questions:

• London dispersion forces: explain that uneven electron movement makes temporary dipoles, which induce dipoles in neighbouring molecules.
• Why water is polar: give the electronegativity difference and the bent shape.
• Catalysts: say they offer another reaction pathway needing less energy to react, so a bigger share of collisions succeed.
• Equilibrium shifts: count the moles of gas on each side before explaining a pressure change.
• Denaturing: describe the change in a protein's shape, not just that it stops working.

Use a daily paper as a short timed prelim

Today's Higher Chemistry paper covers moles and amount of substance, enthalpy and Hess's law, equilibria, redox, periodicity and ionisation energy, bonding and intermolecular forces, rates and energy distributions, and alcohols. It also includes alkanes, alkenes and halogenoalkanes, which aren't in Higher Chemistry, and it doesn't cover the consumer chemistry in Nature's chemistry (fats, soaps, proteins, fragrances, skin care) or have an objective test. Use it alongside the official past papers, remembering that papers before 2027 are longer. For prelim dates, see our prelims guide.

Read next

Scotland · HigherHigher Biology: 2027 Exam Guide and Practice QuestionsHigher Biology explained: the new single 100-mark exam for 2027, the assignment, 2026 grade boundaries, the three areas and worked practice questions.