How to Get an A* in O Level Chemistry (5070): Paper-by-Paper Guide

What do you need to get an A* in O Level Chemistry (5070)?

To get an A* in Cambridge O Level Chemistry (5070), you need a high weighted total across your three papers: multiple choice, theory and one practical paper. Cambridge awards the A* on the overall total, not paper by paper. In the June 2026 series, the A* needed 164 out of 200 (82.0%) for Pakistan's paper combinations.

Cambridge states that grade A* does not exist for an individual component. The A* threshold for each combination of papers is calculated from the A and B thresholds and the maximum mark, and thresholds are set again after every series. There is no fixed A* percentage, so treat past figures as a guide, not a promise.

The June 2026 grade threshold table for 5070 shows how close the routes were:

Variants 12, 22, 32 and 42 are the papers on Cambridge's June 2026 zone 4 timetable, the timetable Pakistan sits. The practical lesson: an A* in 5070 has recently meant dropping fewer than one mark in every five across the whole qualification. For more on how thresholds work, read our guide to what percentage is an A*.

How is O Level Chemistry 5070 structured?

Cambridge O Level Chemistry (5070) has three papers for every candidate: Paper 1 (multiple choice, 30%), Paper 2 (theory, 50%) and one practical paper worth 20%, either Paper 3 (Practical Test) or Paper 4 (Alternative to Practical). The current syllabus covers exams in 2026, 2027 and 2028, and the 2029 syllabus keeps the same structure.

The figures below come from the official 5070 syllabus for 2026, 2027 and 2028:

Papers 3 and 4 test exactly the same experimental skills, and Cambridge provides its "Notes for use in qualitative analysis" with both. If you are a private candidate in Pakistan, you will take the Alternative to Practical; our private candidate registration guide covers the entry options. School candidates should ask which paper their school has entered them for.

Cambridge has also published a 5070 syllabus for 2029, which says there are no significant changes that affect teaching. Whichever year you sit, check that your notes and past papers match the syllabus for that year.

How do you score highly on Paper 1 (multiple choice)?

Paper 1 of O Level Chemistry (5070) is 40 four-option questions in one hour, worth 30% of your grade. That is 90 seconds per question. High scorers read every stem slowly, underline conditions such as "in excess" or "in a school laboratory", and check calculation options rather than guessing between two familiar-looking answers.

Cambridge's June 2024 principal examiner report shows where multiple-choice marks went. Candidates:

• ignored "in excess" in the question stem and chose an answer that would otherwise be correct
• confused the number of molecules in a sample with the number of atoms
• assumed an endothermic reaction makes the mixture's temperature rise (just over half of candidates chose this wrong option on one paper)
• calculated an Rf value from raw ruler readings instead of measuring both distances from the baseline
• named an ester as a propanoate instead of a butanoate, forgetting the carbon in the ester group

None of these are hard chemistry. They are reading and precision errors, which is good news: they respond quickly to practice.

How do you write top-band answers in Paper 2 (Theory)?

Paper 2 of O Level Chemistry (5070) is worth 50% of your grade, so it decides most A* results. Top answers show every step of calculations, use exact scientific terms, include state symbols when asked, and answer precisely what the command word requires. Most lost marks come from vague wording and incomplete answers, not unfamiliar chemistry.

The June 2024 examiner report gave clear messages for the theory papers:

• Show your working. Better performing candidates showed calculations in full, so a wrong final answer could still earn error-carried-forward credit.
• Practise balanced equations with state symbols. Many candidates wrote incorrect formulae (for example, calcium hydroxide as CaOH), which made balancing impossible.
• Name particles exactly. Say whether you mean an atom, a molecule or an ion. Writing "iodine" when the answer needs "iodide" loses the mark.
• Talk about the position of equilibrium. The examiners wrote that it is the position of equilibrium that moves, not "the reaction".
• Answer the whole question. A colour change needs the starting and the final colour, and an answer requested to two significant figures must be given to two significant figures.

Rate questions are a good example. Saying "more collisions" is not enough; examiners wanted more of the collisions to be successful, with particles mentioned explicitly.

Learn the syllabus command words too. Cambridge defines "state" as "express in clear terms", while "explain" means setting out reasons or how and why, supported with evidence. A one-word answer to an "explain" question cannot reach full marks.

How do you prepare for Paper 3 or Paper 4 (practical)?

The practical paper is worth 20% of O Level Chemistry (5070) and is the most predictable part of the exam. Both Paper 3 and Paper 4 test the same skills: choosing apparatus, taking readings, recording observations, identifying ions and gases, processing data, and planning and evaluating experiments. Regular practice with real or past-paper experiments turns this paper into reliable marks.

The syllabus lists the experimental contexts you may meet, including titrations, rates of reaction, salt preparation, electrolysis, separation techniques such as chromatography and distillation, temperature changes, and identification of metal ions, non-metal ions and gases.

For the Alternative to Practical, the June 2024 examiner report advised candidates to:

• use the same precision as the data already given in the question
• use the "Notes for use in qualitative analysis" printed in the paper, and still know procedures that are not in the notes, such as flame tests
• explain how to make results accurate when a planning question asks for it
• read every instruction, because rushed candidates missed key information

The report also noted that candidates need real experience of practical work to understand experiments described on paper. Even if you sit Paper 4, watch or carry out titrations and gas tests where you can, so the apparatus is familiar. Practise reading burettes, thermometers and measuring cylinders from diagrams, and record observations ("effervescence", "white precipitate, soluble in excess") rather than conclusions unless identification is asked for.

Which topics cost students the most marks?

The 5070 syllabus has twelve topics, and Cambridge's June 2024 examiner report shows that organic chemistry, equations, energetics and precise explanations lose the most marks. Candidates in June 2024 found organic chemistry challenging on both theory papers, often struggling to name or draw the products of reactions. Weak equation writing and vague bonding explanations followed closely.

Based on the June 2024 examiner report, prioritise these areas:

Our O Level Chemistry page lists all twelve topics with the mistakes our tutors see most often. Students planning A Level Chemistry should treat stoichiometry, bonding and organic chemistry as foundations, because the A Level course builds directly on them.

What does an A* revision plan for O Level Chemistry look like?

An A* revision plan for O Level Chemistry (5070) finishes the content first, then moves to topical past-paper questions, then to full timed papers marked against official mark schemes. Start at least four to five months before the exams, give Paper 2 the largest share of time, and practise one practical-paper question every week.

Cambridge designs O Level syllabuses around 130 guided learning hours per subject, so most of the learning happens during the course; revision is about turning knowledge into exam marks. A sample plan for a June candidate:

Check your own series dates rather than assuming the order. In the June 2026 zone 4 timetable, Paper 2 was on 28 April, the practical papers on 7 May and Paper 1 not until 9 June, so multiple-choice practice had to continue after the other papers. Look up current dates on our exam dates page, find official papers through our past papers guide, and compare your scores with recent O Level grade boundaries.

If you miss the grade, Cambridge allows candidates to retake the whole qualification as many times as they want, in the June or November series.

Getting help

Heights International Academy offers live online O Level Chemistry tutoring for the 5070 syllabus, one to one or in small groups, built around the papers where you lose the most marks. No tutor can honestly guarantee an A*, but a structured plan and expert feedback make it far more reachable. Pakistani students should also read our O Level in Pakistan guide, and you can book a free trial class before you commit.