HSC Chemistry exam (NESA): format, timing and marking

The HSC Chemistry exam is one paper out of 100 marks, with 5 minutes of reading time and 3 hours of working time. Section I is 20 multiple-choice questions at 1 mark each, and Section II is 80 marks of written questions, each worth 2 to 9 marks in the 2023, 2024 and 2025 papers. In 2026 it is on Friday 30 October, starting at 9.25 am, and you need a NESA-approved calculator.

This guide describes the papers set under the Chemistry Stage 6 Syllabus (2017) from 2023 to 2025 and the logistics of the 2026 exam. For every past paper and the questions inside them, go to HSC Chemistry past papers (NESA). For the mark weightings by module and dot point, see HSC Chemistry most tested topics.

What is the HSC Chemistry exam paper like?

The cover page of each of the 2023, 2024 and 2025 papers sets out the same structure.

The number of Section II questions and their sizes change from year to year, but the totals do not.

Counted from the three papers, not from a NESA summary. Some Section II questions have parts, such as Question 27 in 2025 (a), (b) and (c), and the marks shown are for the whole question.

Section I questions in the 2025 marking guidelines are tagged to Modules 5, 6, 7 and 8: five to Module 5, four to Module 6, six to Module 7 and five to Module 8. The 2023 and 2024 mapping grids also tag every question to Modules 5 to 8 and to no other module, so a calculation or a graph question is still counted under one of the four content modules.

The sums for time are simple. Section I at 35 minutes is about 1 minute 45 seconds a question. Section II at 2 hours and 25 minutes is 145 minutes for 80 marks, or about 1.8 minutes a mark, which makes a 5-mark question a nine-minute job and a 2-mark question a three-and-a-half-minute one.

When is the HSC Chemistry exam in 2026?

NESA's 2026 timetable puts Chemistry on Friday 30 October, 9.25 am to 12.30 pm. The printed start is when reading time begins, so 5 minutes of reading followed by 3 hours of writing ends at 12.30 pm. It is in the third week of the written exam period, which runs from 13 October to 5 November.

NESA's rules ask you to arrive at least 10 minutes early for an exam other than the first English one. During reading time you can read the paper but not write, mark it or use any equipment, including a highlighter. You can't leave in the first hour or the last 15 minutes. Full rules, illness/misadventure applications and the rest of the exam period are in how to prepare for HSC exams.

What can you take into the HSC Chemistry exam?

NESA's equipment list names an approved calculator for Chemistry. An approved calculator cannot be programmable or have graphing, CAS or inbuilt financial functions, and your calculator must be switched off and reset before you go in. General items such as black pens, pencils and a ruler are in the equipment list, and the paper itself tells you to draw diagrams in pencil.

The paper provides a formulae sheet, a data sheet and a Periodic Table at the back, so you don't carry them in. What each sheet holds, what is missing and how questions use them is in the HSC Chemistry data sheet and formulae sheet guide. Practise from the full paper so the sheets are in front of you when you work.

How does NESA mark the HSC Chemistry exam?

NESA publishes the marking guidelines in each year's exam pack. Section I has an answer key of one letter per question, and each question is one mark. Section II questions have criteria with a mark beside each one, and often a sample answer.

For a 2-mark question the criteria are literal. In 2025, Question 21 gave the marks this way:

The sample answer was UV light and 2-bromobutane. Under these criteria, a response that names the product correctly but gets the condition wrong still earns 1 mark. Each of the two things asked for carries its own mark, so leaving one out forfeits that mark even when the other is right.

Longer questions switch from counting parts to describing how well you did the whole task. The 2025 Question 36 was out of 7 and asked for the predicted spectra from four techniques. Its criteria ran in levels:

Two things move a response up a level. Coverage comes first (all four techniques against most or some), then the quality of the link between the structure and the evidence. Instead of a single sample answer, the guidelines list what answers could include for each technique, with values. NESA notes that sample answers are not intended to be exemplary or even complete responses. For a 4-mark question such as 2025 Question 37, the top criteria are determining the structure of compound A and justifying it using all the data provided, so a correct structure with only some of the data used loses a mark.

NESA aligns your raw exam marks to the performance band standards, and your HSC mark is the average of that exam mark and your moderated assessment mark. That step is covered in HSC bands and HSC results.

How do you approach the HSC Chemistry multiple-choice section?

Section I is 20 questions and 20 marks, one letter each, with answers recorded on the separate multiple-choice answer sheet. The 2025 marking guidelines tag every Section I question to Modules 5 to 8, so the section samples all four content modules and no single module carries it.

NESA publishes no feedback on Section I. Its Chemistry feedback for 2024 and 2025 starts at Question 21, so there is no board commentary on how students went on the multiple-choice questions. What we can add is our own data, and it comes with the usual caveat. Across 26,273 marked multiple-choice attempts on HSC Chemistry questions from board external papers, AusGrader users average 57.5%, against 63.9% on short-answer questions (5,858 attempts). These are self-selected users practising when they chose to, so the figures show where practice is needed and are not a cohort result. The question-type table sits in HSC Chemistry hardest topics.

Three things follow from the paper itself:

• Budget about 1 minute 45 seconds a question. The paper's 35 minutes is a suggestion, and it puts 20 marks in about a fifth of the working time.
• There is no working to rescue you. The answer key is a single letter, so a misread stem and a wrong calculation cost the same mark. Do calculations on the question paper, where you can check them before you choose a letter.
• Check every question has an answer. Nothing in the marking guidelines describes a deduction for a wrong answer, and a blank cannot earn the mark.

How do you approach Section II of the HSC Chemistry exam?

The Section II booklet states two instructions that matter. The answer spaces provide guidance for the expected length of response, and you should show all relevant working in questions involving calculations. Extra writing space is at the back of the booklet. If you use it, indicate which question you are answering.

NESA's General feedback for Chemistry is identical in 2024 and 2025, and it is a good checklist. Paraphrased, it says students should:

• read the whole question so no component is missed
• understand the key words and the intent of the question
• plan the answer so the information comes in a logical order
• use relevant scientific terms
• engage with the stimulus material and refer to it
• show working, with units and significant figures
• write a logical and succinct answer
• review the answer against the question requirements

The per-question feedback shows what each of those looks like when it goes wrong.

What costs marks in HSC Chemistry Section II?

The table below pairs what NESA's 2024 and 2025 feedback says better responses did with the weaker habit it names. The wording is ours, and each row names the question it comes from.

Because the 2024 and 2025 General feedback is word-for-word the same, treat the list above as standing advice and not a one-off. NESA's feedback does not mention pacing, handwriting or memorised answers, so none of that appears here as board advice.

How should you prepare for the HSC Chemistry exam?

Start from the topics. The most-tested and hardest-topics guides give the mark weightings by module and the topics where AusGrader users drop the most marks, and those two pages are where to decide what to revise first. See HSC Chemistry most tested topics and HSC Chemistry hardest topics.

Then practise the exam itself:

1. Use the full paper. Print the whole PDF, formulae sheet, data sheet and Periodic Table included.
2. Time it. 35 minutes for Section I, then 145 minutes for Section II, with 5 minutes' reading first.
3. Mark against the criteria. Mark yourself against NESA's marking guidelines, using the level descriptors for longer questions, not just the sample answer.
4. Keep a list of lost marks. Sort each lost mark into read the question, specific term, stimulus, working or graph. Those groupings come from NESA's feedback above, and your list will show which one is yours.

The HSC Chemistry question bank holds NESA past-paper questions with the marking criteria attached, so each answer can be marked against the criteria NESA used. Our guide to HSC past papers covers where to get every year's paper.