WACE Chemistry ATAR Exam 2026: Format and Marks (SCSA)

Quick answer. The WACE Chemistry ATAR exam is one written paper with ten minutes of reading time and three hours of working time. SCSA's examination design brief sets 25 multiple-choice questions, a short-answer section and an extended-answer section, weighted 25%, 35% and 40% of the exam, with 15-20% of the paper in calculations. You may use up to three non-programmable calculators with a supplied Data booklet. In 2026 it is sat on Thursday 29 October at 9.20 am, and it makes up half of your combined mark for the course.

This guide describes the Year 12 ATAR course examination (Units 3 and 4) as set from 2020 to 2025 and as scheduled for 2026, under the Year 12 syllabus effective from 1 January 2024. SCSA publishes each year's structure on the cover of that year's paper, so check the 2026 cover page on the day. Everything here about what costs marks comes from the 2024 and 2025 examination reports, which describe the cohorts that sat those papers. For every Chemistry paper and marked practice question, see WACE Chemistry past exams (SCSA).

When is the WACE Chemistry exam in 2026?

Chemistry is on Thursday 29 October 2026, with a 9.20 am start, in the first week of the written exams. SCSA's timetable states that it is final and that no changes will be made. The default ten minutes of reading time applies, and Chemistry is not one of the courses with a shortened working time. Every other exam date is on the WACE exam timetable 2026 (SCSA).

Chemistry has no practical examination. It is absent from SCSA's practical timetable and from the table of practical weightings in the WACE Manual, so the written paper is the whole ATAR course examination.

What is the format of the WACE Chemistry exam?

The Chemistry syllabus (2024 version, p. 21) carries the examination design brief. It fixes the following:

Calculations make up 15-20% of the exam and sit in Sections Two and Three. The instructions to candidates require you to show working or reasoning clearly and to give numerical answers to the appropriate number of significant figures, with units where they apply. The brief gives percentages and question ranges but no mark totals, which is why the raw marks below vary by year.

The structure table printed on the 2025 paper is below. The 2020 to 2025 papers share the same section names, question counts in Section One, suggested times and percentages, all within the brief above.

What changes each year is the number of questions and raw marks in Sections Two and Three. The percentages do not change.

The Section Three questions are long. On the 2025 paper the six questions ran from 14 marks (Question 39) to 25 marks (Question 35), each split into lettered parts. Question 37 (16 marks), for example, mixed a calculation with two explanations.

How much of your Chemistry result is the exam?

Chemistry has no practical component, so SCSA combines your moderated school mark with your ATAR course written examination mark by taking their average. The exam is therefore half of the combined mark. The other half is your moderated school mark, which the syllabus builds from four school-based assessment types:

The 50% examination in this table is your school's own exams, not the ATAR course written examination, so school exams set to the design brief above are half of your school mark as well. The 20% for science inquiry is one combined figure, and the syllabus gives no split between practical work and investigation. Students must complete at least one investigation across the pair of units, each assessment type must appear at least once, and the tasks must sample the content of both Unit 3 and Unit 4 (syllabus pp. 18-19). Your school sets the task list and the weighting of each task in an assessment outline. You must sit the exam to receive a mark or grade for the course, unless an approved Sickness/Misadventure Application covers it. How the combined mark becomes a scaled score and an ATAR is TISC's process, covered in WACE ATAR: how it's calculated.

What can you take into the WACE Chemistry exam?

• Calculators: up to three, none of which can create or store programs or text. Any brand or model is allowed.
• Data booklet: supplied by the supervisor with the Question/Answer booklet and the multiple-choice answer sheet. You do not hand it in. What it contains is covered in the next section.
• Stationery: blue or black pens (preferred), pencils including coloured, sharpener, correction fluid or tape, eraser, ruler and highlighters.
• Reading time: reading only. SCSA's rules bar marking the paper in any way and using a calculator, and writing or using a calculator in reading time is listed as a breach with a penalty of 5% of the written examination mark.

The remaining exam-day rules are in How to prepare for WACE exams (SCSA).

What is in the 2026 WACE Chemistry data booklet?

The 2026 booklet is eight pages, and SCSA states it is valid for teaching and examining until 31 December 2026. It is SCSA's copyright, so this guide describes it and does not reproduce its tables. Open the official 2026 Chemistry data booklet alongside this section.

• Periodic table (p. 3). A full-page table, with the IUPAC 2018 periodic table credited as its data source.
• Formulae (p. 4). Only six: moles from mass and molar mass, moles of solute from concentration and volume, moles of a gas at STP from its volume and the molar volume, the ideal gas law, parts per million (mg of solute per kg of solution) and pH, which is $\text{pH} = -\log_{10}[\text{H}^+]$.
• Units and constants (p. 4). Volumes in L or mL, temperature in degrees Celsius or kelvin (taking 0.0 degrees Celsius as 273.15 K), energy in kJ, pressure in kPa, and concentration in mol/L, g/L or ppm. Constants given are the gas constant in joules, the Avogadro constant, the molar volume of an ideal gas, the definition of STP as 0.0 degrees Celsius and 100.0 kPa, and $K_w$ for water at 25 degrees Celsius.
• Solubility rules (p. 4). Two tables, one for ionic solids that are generally soluble and one for those that are generally insoluble, each with exceptions. Exceptions are split into insoluble, soluble and slightly soluble, and the thresholds are stated: soluble means more than 0.1 mol dissolves per litre, slightly soluble between 0.01 and 0.1 mol, and insoluble less than 0.01 mol.
• Colours (p. 5). General rules for ionic solids, then lists of exceptions, coloured ions in solution, other coloured substances and the colours of the halogens as elements, in water and in an organic solvent.
• Alpha-amino acids (pp. 6-7). Twenty α-amino acids with their names, three-letter symbols and structures.
• Standard reduction potentials (p. 8). One table of 42 half-reactions at 25 degrees Celsius, from fluorine at the most positive end to potassium at the most negative, with the hydrogen half-cell set at zero.

What the booklet does not give matters as much. It prints no formula for concentration from moles and volume (you rearrange $n = cV$), dilution, enthalpy, rates, $K_a$, $K_c$, percentage yield or cell potential. It has no bond energies, enthalpies of formation or combustion, specific heat capacities or indicator ranges. The gas constant is in joules while pressure is in kPa and energy in kJ, so check units whenever you use the ideal gas law.

Past papers send you to the booklet for specific things, such as the colours to use when you write observations (2023 and 2024 papers) and the side chains of the α-amino acids (a 2022 question). The 2025 examination report asks teachers to make sure students know the booklet's contents and can use it efficiently, so open it during practice, not for the first time in the exam room. The 2026 booklet is the one for this year's exam; whether later booklets differ is not stated in the syllabus.

What changes in the WACE Chemistry exam from 2027?

Nothing in the examinable content or the exam. SCSA's Year 12 syllabus for teaching from 2027 (effective 1 January 2027) has the same Unit 3 and Unit 4 content, the same school-based assessment types and weightings (20%, 10%, 20% and 50% for school examinations), the same grade descriptions and the same examination design brief, including the 25%, 35% and 40% sections, as the 2024 syllabus. A word-by-word comparison of the two documents found differences only in the front matter:

• Rationale (2027 syllabus p. 1). Rewritten, with a new paragraph naming the Year 12 topics: equilibrium, acid-base behaviour, oxidation and reduction, and the structure, properties and reactions of organic functional groups, plus chemical synthesis.
• Aims (p. 2). Reworded slightly. The first aim drops its reference to the "ever-changing world".
• General Capabilities (pp. 5-6). Now described as not assessed unless identified within the specified unit content. Year 11 and Year 12 Chemistry both tick only Critical and creative thinking, Literacy and Numeracy.

The 2027 syllabus does not apply to the 2026 exam, which follows the 2024 syllabus. It also does not say whether the data booklet or the marking conventions change for 2027, and no 2027 data booklet was available when this guide was written. For the full syllabus content, see the WACE Chemistry ATAR syllabus (SCSA).

What does each section ask for?

Section One: multiple choice. Twenty-five questions, one mark each, answered on a separate sheet. The paper states that marks are not deducted for incorrect answers, and that shading more than one box earns nothing. The one exception to single answers is a question the key itself says accepts two: the 2025 Marking Key lists Question 6 as "c and d". The reports describe the section as answered well in both years, with means of 72.87% in 2024 and 72.11% in 2025. In 2025 the hardest, Question 9, needed three facts held at once: recognising that rust is a mixture of hydrated iron oxides and hydroxides, that the iron in it is in the +3 state and that it is a solid. In 2024 the hardest three were about justifying an indicator choice from hydronium and hydroxide concentrations, spotting sources of error in a titration, and evaluating uses of a polymer.

Section Two: short answer. Eight to ten questions across 2020 to 2025. In 2024 the questions named as most challenging were explanations and applications: explaining solubility, explaining ocean acidification from equations the paper provides, and an application of buffers. The 2025 paper opened the section with a 10-mark question (Question 26) asking for balanced equations for sets of substances together with the expected observations, and the report names Question 26 as one of the two most challenging in the section. Drawing was answered best in 2025, in particular drawing three isomers with all atoms and bonds shown.

Section Three: extended answer. Five or six questions, each with several lettered parts. The two 2025 examples were built around a three-step synthesis route and a plant hormone pathway with titration data. The 2025 report tells candidates to use the ten minutes of reading time to read the Section Three passages carefully. The part named as hardest in 2025 was the Question 37(c) explanation of why nonanoic acid and methanol differ in solubility in water, and in 2024 it was Question 36(a), outlining and justifying the best conditions for a reaction.

Explaining solubility is among the most challenging questions the reports name in both years: in Section Two in 2024 and in Section Three in 2025. Practise it with the topic questions on the Chemistry hub, and see WACE Chemistry most tested topics for how the marks fall between Units 3 and 4.

How long should you spend on each section?

The suggested working times are 50, 60 and 70 minutes, which total the full three hours. On the 2025 paper that is about 2 minutes per mark in Section One, 0.92 in Section Two (60 divided by 65) and 0.62 in Section Three (70 divided by 113). Those ratios move with each year's mark totals, so read the section mark totals on the cover page during reading time and set your own pace from them.

SCSA's reports for both years ask teachers to give students practice under timed conditions, with contexts that cannot be answered from rote-learned responses. A Section Three question of 14 to 25 marks cannot be rescued in the last five minutes, so reading time is best spent finding the big questions and the passages.

How does the marking key award marks?

Every Chemistry Marking Key lists, for each part, the separate ideas that earn one mark each. Writing one fluent paragraph does not earn more than hitting each idea once. The 2025 Question 37 shows the pattern. Part (c), 6 marks, asked for an explanation of the difference in solubility of nonanoic acid and methanol in water. The key (adapted and shortened here) awards one mark for each of these:

The key adds that responses framed as the strength of the forces, or the energy needed to overcome attractions, are accepted. Two things follow. First, a six-mark "explain" needs six identifiable statements, so count them against the marks. Second, three of the six marks are for naming the specific forces for the specific species, which is exactly what both examination reports tell candidates to do.

Part (a) of the same question, 7 marks, was a calculation of the mass of buta-1,3-diene needed per day. The key gives one mark to each stage: the mass of nonanoic acid made daily, its amount in moles, the 1:1 ratio to the ester, the 2:1 ratio to the diene, the mass at 100% efficiency, the correction for 72% efficiency, and the final answer to the appropriate significant figures, $2.5 \times 10^{6}$ g. The final mark is for the significant figures, and both reports also advise rounding only in the final answer.

What do SCSA's examination reports say costs marks?

The 2024 and 2025 Chemistry reports overlap heavily, so these are the points both repeat. They are paraphrased from the reports.

• Generic terms. Name the specific intermolecular forces for the species in the question. The reports' examples are dipole-dipole forces (2024) and ion-dipole forces (2025).
• Calculations. Write every number out on each line instead of using empty brackets or arrows to mean "same as above", because a later arithmetic slip leaves no working to mark. Round only in the final answer, give standard units and sensible significant figures, and in 2024 convert masses to grams.
• Equations. Balance both atoms and charge in ionic equations, and use single and double arrows correctly.
• Observations. Record what is seen from before the reaction through to the end. Do not name the chemicals. Describe a metal as a silver, grey or otherwise coloured solid, and a solution as colourless or coloured, never only "clear". Watch words like "excess" and "limited", which decide what you should see. A "colourless, odourless gas" is an inference, whereas colourless bubbles forming in a liquid can be observed.
• Explanations. Longer explanations were the weak point of the 2025 paper, mainly through too little detail for the marks. The 2025 report also says Le Châtelier's principle can predict a change in an equilibrium system but should not be used as the explanation, and that collision theory should explain what is happening. The 2024 report tells candidates to decide which of the two the question needs.
• Language. Do not use arrows for "increases" or "decreases". Spell out an acronym the first time. Do not give chemical species intentions: the 2024 report discourages "sensitive" for enzymes and pH or temperature, and the 2025 report says species do not make choices.
• Organic structures. Bonds must join the correct atoms, functional groups must be explicit, and you should check whether the question wants a full structural, condensed or molecular formula. The 2025 report also asks for fluency with every concentration unit in the syllabus and with converting between them.
• Rote answers. The 2025 report asks for an understanding of the concepts, processes and systems in the syllabus instead of memorised answers, and both reports ask teachers to set practice contexts that rote-learned responses cannot answer.

How the cohort did, from the same reports:

SCSA called both papers fair and valid. Our own marked-attempt data points the same way on the longer explanations: see WACE Chemistry hardest topics, which reports AusGrader users' scores by command verb. That sample is self-selected and does not describe the SCSA cohort. For what each key word in a question asks you to do, see WACE command words explained.

What mistakes cost the most marks in WACE Chemistry?

The pairs below illustrate contrasts the 2024 and 2025 reports draw.

How should you practise for the WACE Chemistry exam?

Both reports ask teachers to have students use past marking keys when checking practice answers, and the Marking Key breakdown above shows why: you can count the ideas your answer hit against the marks available. AusGrader marks questions from the SCSA Chemistry papers against the key and returns a mark for each. Start with WACE Chemistry most tested topics to order your revision by marks, then work through WACE Chemistry hardest topics for the dot points where students drop the most. For the course content itself, see the WACE Chemistry ATAR syllabus (SCSA).