QCAA Chemistry External Exam: Format, Marks and Timing (QCE)

The QCAA Chemistry external exam is two papers, each with 5 minutes perusal and 90 minutes working time, written and marked by QCAA and worth 50% of your QCE Chemistry result. It is a combination response exam on Units 3 and 4: multiple choice, short answers, calculations and unseen stimulus. A QCAA-approved graphics or scientific calculator is permitted and the QCAA Chemistry formula and data book is provided.

This guide describes Chemistry 2025 v1.0, which applied to Year 11 from 2025 and Year 12 from 2026, so the 2026 paper is the first sat under it. The subject reports for 2022 to 2025 describe cohorts assessed under the earlier 2019 syllabus. Their commentary on exam technique still applies, and the conditions below are the 2025 ones. For the whole subject, start at the QCE Chemistry study guide, and for the papers themselves go to the QCAA Chemistry past papers.

What is the QCAA Chemistry external exam?

Two papers set by QCAA, the same for every school, on the same day under the same conditions. The external examination carries 50% of your result. The other 50% is the three internal assessments, which your school sets and marks and QCAA then confirms. The study guide has the full weighting table.

It examines four of the six syllabus objectives: describe, apply, analyse and interpret. Evaluate and investigate are not examinable, so they are assessed only in the internals. The syllabus says questions may require:

• multiple choice
• single words, sentences or paragraphs
• calculating using algorithms
• interpreting unseen stimulus such as graphs, tables or diagrams

Only Units 3 and 4 are examined. Units 1 and 2 are formative and your school sets those assessments, so there is no external exam in Year 11.

How long is each paper, and what can you bring?

QCAA publishes a list of approved graphics calculators and a list of approved scientific calculators, and its 2026 memo to schools says both were updated. Check your model against the current lists on the exam timetable page, which links them. For what the formula and data book contains and where it stops helping, see the Chemistry formula and data book guide.

How many marks is the exam, and how do you split your time?

The syllabus fixes the format, not the mark total or the split between papers. The numbers come from the papers as sat:

• Paper 1 opened with 20 multiple-choice marks in each of 2022, 2023, 2024 and 2025, followed by a short-response section of 31 to 38 marks.
• Paper 2 was a short-response paper of 49 to 55 marks.
• The total was 100 marks in 2022 and 110 or 111 from 2023 to 2025. In 2025 each paper was worth exactly 55 marks.

On the 2025 shape, 90 minutes for 55 marks leaves about 98 seconds a mark. That figure is our arithmetic from the report, not a QCAA number. In Paper 1 the multiple-choice marks come out of the same 90 minutes, so a rehearsal on a 2022 paper, which was out of 100, is a little gentler than the paper you will sit.

The mark count in a question is also your guide to how much to write. QCAA's 2025 report says a question needing a prediction and an explanation of reasoning for 3 marks would typically need the prediction plus two points of explanation.

When is the QCAA Chemistry external exam?

In 2026 both papers sit on Friday 30 October: Paper 1 in the morning session and Paper 2 in the afternoon session, each with 90 minutes working and 5 minutes perusal. QCAA's timetable lists sessions as AM or PM and not as clock times, so take your start time from your school's exam schedule. The full 2026 period, with clash rules and every other subject, is on the QCAA external exam timetable.

What changed for the 2026 Chemistry exam?

QCAA's July 2026 summary of changes for external assessment lists these for Chemistry:

• Green chemistry principles, atom economy and molecular manufacturing are now assessed within internal assessment, as part of Science as a human endeavour. They are no longer in the external exam as Science understanding.
• Perusal time is 5 minutes. It was 10 minutes under the 2019 syllabus.
• Calculator conditions were clarified. The 2025 syllabus allows a graphics or scientific calculator, where the 2019 wording named a graphics calculator only.
• The formula and data book has been updated and now includes the reaction pathway diagram.

If you practise on older papers, treat their content with the 2025 syllabus beside you. Work for technique any item that has left the syllabus, and keep your content revision to the current dot points. The most tested topics guide shows how the 2020 to 2025 papers spread their marks across the four topics.

What do the multiple-choice questions look like?

Twenty questions, each worth one mark, all in Paper 1. QCAA prints the percentage of students choosing each option in the subject report, and the pattern is more useful than the average. In 2025 the hardest item was Question 9, where 30.65% chose the correct option and 36.34% chose B, so more students picked a wrong answer than the right one. In 2022 three items did the same: Question 5 (30.51% correct, 44.53% on option C), Question 10 (32.27% correct, 37.40% on C) and Question 14 (30.40% correct, 31.11% on A).

Plenty of items are easy, so the paper is not uniformly hard. Question 17 in 2025 was answered correctly by 93.62%. The marks are lost on the items where a plausible misconception is written into a distractor.

Those percentages come from cohorts assessed under the 2019 syllabus, and they describe individual questions, not the 2026 paper.

What does QCAA say costs marks in the short-response questions?

QCAA's 2025 report names three things to strengthen:

• Chemistry conventions. Ionic charges and states of matter in redox reactions. Equilibrium arrows for the partial dissociation of a weak acid and reaction arrows for the full dissociation of a strong acid. Oxidation states written with the sign before the number (+3) and ionic charges with the magnitude before the sign (2+).
• Addressing every part of the question. The cognitive verb and the type of response it needs, sized to the marks available.
• Specific reactions and their conditions. Electrolysis of dilute, concentrated and molten salt, the hydrogen fuel cell under acidic and alkaline conditions, and organic pathways with the conditions under which each reaction occurs.

The recurring problems across all four reports, and how they connect to your cognitive verbs, are in the study guide. What is specific to the exam is how they show up in individual questions. These come from the reports' own commentary on named items.

The 2023 compare question shows the shape compare wants: a similarity, a difference and the significance of the difference. QCAA's reports for 2022 and 2023 both single that out.

How should you use past papers to prepare?

Sit a paper's questions under timed conditions, mark yourself against the marking guide, and write down what each lost mark was: wrong content, misread stimulus, missing convention or too few points for the marks. Those causes need different fixes. Each exam's questions and marking guide are published by QCAA, and the AusGrader subject page holds the 2020 to 2025 questions as marked past-paper questions, so you can check your method and your answer.

Across 51,399 marked attempts on QCE Chemistry questions on AusGrader, verbs that ask you to produce an answer score well below recognition: calculate averages 56.2% (1,048 attempts), justify 59.2% (284) and explain 59.5% (3,476), against identify at 82.6% (3,407). That is our self-selected sample, not a state result, and it agrees with the pattern in QCAA's reports. The full breakdown by verb, topic and paper is in the hardest topics guide.