AQA A Level Chemistry (7405) Past Papers 2026

7405/1 — Inorganic and Physical Chemistry

Duration: 2h

7405/2 — Organic and Physical Chemistry

Duration: 2h

7405/3 — Practical and Synoptic

Duration: 2h

Buffer solution preparation and pH change mechanism

Only 5% of students scored all marks in 2022; many identified mixing ethanoic acid with potassium hydroxide but failed to state the acid must be in excess, and could not explain buffer resistance by naming the ethanoate ions reacting with added H⁺.

Paper 1

Detection of ions at the mass spectrometer detector — current proportional to abundance

Only 21% scored both marks in 2022 and the question was poorly answered in 2023; most students did not state that the ion gains an electron at the detector to produce the current, nor that the current is proportional to the abundance.

Paper 1

Standard electrode potential notation and cell potential calculations

Only 7% scored both marks in 2022; students confused the sign convention and could not apply the correct direction of the cell reaction. In 2023 many thought the cell was rechargeable.

Paper 1

Levels-of-response qualitative analysis — full description of ion tests

Level 3 was rarely achieved in both 2022 and 2023 Paper 3; students omitted warming NaOH when testing for NH₄⁺, failed to acidify BaCl₂ when testing for sulfate, and stopped the Al³⁺ test at the white precipitate without describing its redissolving in excess NaOH.

Paper 3

Explanation of base strength in amines — availability of lone pair on nitrogen

Despite being tested in numerous prior papers, this question still discriminated well in Paper 2 (2022); few students could explain how substituent effects alter the availability of the lone pair on nitrogen.

Paper 2

Maxwell–Boltzmann distribution — axes, shape at higher temperature, link to Ea

High discrimination index in Paper 2 (2023); common errors included reversing the axes labels and failing to show how the increased temperature changes the distribution, specifically the shift of the peak and the greater area beyond Ea.

Paper 2

Born–Haber cycle — electron affinity factors of 2 and correct sign conventions

In Paper 1 (2023) Q05.5, many students missed one or both factors of 2 for atomisation and electron affinity of chlorine and struggled to evaluate combinations of positive and negative values correctly.

Paper 1

Polarity and dipole moment — linking polar bonds to asymmetric molecular shape

Many students in Paper 3 (2023) Q05.2 implied that polarity causes hydrogen bonding, reversed the logic; they failed to identify the shapes of all three molecules and link asymmetry to a net dipole moment.

Paper 3