How to Revise IGCSE Chemistry (The Method That Actually Moves Grades)

Cambridge releases the 0620 mark schemes, the grade thresholds and a decade of past papers. Every student has the same materials. The students who get A* are not smarter. They revise differently. The difference comes down to three habits: testing instead of reading, spacing instead of cramming, and marking their own work like an examiner.

Active recall beats re-reading, and it isn’t close

Re-reading a chapter feels productive because the content looks familiar by the third pass. Familiarity is the trap. The exam never asks “does this look familiar?” It asks you to write the test for ammonium ions, from memory, under time pressure.

Active recall flips the process. Close the book, then produce the answer:

• Cover your notes on acids, bases and salts and write out the three salt-preparation methods with one example each.
• Sketch the periodic table trends for Group I and Group VII without looking.
• Write the ionic half-equations for the electrolysis of concentrated aqueous sodium chloride, then check.

Each failed attempt tells you exactly what to restudy. Each successful attempt strengthens the memory far more than another read-through. A 2013 review by Dunlosky and colleagues rated practice testing as one of only two high-utility revision techniques; highlighting and re-reading rated low. Your own experience will confirm it within a week.

Spaced repetition: built for ion and gas tests

0620 contains a block of pure memory work: the qualitative analysis tables. Flame colours, hydroxide precipitates, the four gas tests, the tests for water and for halide ions. These appear in the MCQ papers, the theory papers and Paper 6: the same facts, recycled every session.

Memory work responds to spacing. Make a flashcard deck (paper or an app like Anki) and review on an expanding schedule: day 1, day 3, day 7, day 14, then weekly. A card you get right moves to a longer interval; a card you get wrong resets to tomorrow. Ten minutes a day holds the entire qualitative analysis section in memory permanently. Compare that with the student who crams the tables the night before and confuses copper(II) with iron(II) under pressure.

Our guide to every ion and gas test lists the full set worth carding.

The past-paper method (not just “do past papers”)

“Do past papers” is advice everyone gives and almost no one explains. The method that works has four steps:

1. Timed, closed-book. Sit the paper in the real time limit. Paper 4 is 1 hour 15 minutes for 80 marks. Train at that pace or the back questions will always be rushed.
2. Mark with the real mark scheme. Not your impression of the answer: the exact scheme. Notice which word earns the mark. “The reaction gives off heat” scores nothing where the scheme demands “exothermic”.
3. Log every lost mark in an error book. One line each: paper, question, why lost (knowledge gap, misread command word, arithmetic slip, vague phrasing).
4. Re-sit the failed questions a week later. This is the step students skip and the step that converts marking into marks.

Read how to use 0620 past papers properly before you burn through your stockpile: papers done badly early are papers you can’t sit fresh later.

Topic triage: spend hours where the marks are

Not all 12 topics deserve equal time. Triage in three bands:

• High-yield, high-difficulty: stoichiometry (mole calculations feed into questions across both theory papers), organic chemistry, electrochemistry. These reward repeated problem-solving.
• High-yield, memory-based: acids, bases and salts; qualitative analysis; periodic table trends. These reward flashcards and spacing.
• Lower-weight: states of matter, separation techniques. Secure them, then move on.

Run a diagnostic: one full past paper, marked honestly, sorted by topic. Your three lowest-scoring topics get half your revision hours until the gap closes. Re-test in two weeks with a different paper.

A weekly structure that holds together

Here is a realistic week for a student two months out, alongside school and other subjects:

Day	Session (40-60 min)
Monday	Flashcards (10 min) + active recall on weak topic 1
Tuesday	Topic-sorted past-paper questions, weak topic 1
Wednesday	Flashcards + active recall on weak topic 2
Thursday	Topic-sorted questions, weak topic 2
Saturday	One timed paper section + full marking and error log
Sunday	Re-sit last week’s failed questions + plan next week

Friday is deliberately free. A schedule with no slack collapses the first week something comes up, and in a Malaysian school calendar, something always comes up.

One warning sign worth acting on: if your error log keeps showing the same mistake (moles, again, for the third week), self-study has hit its ceiling on that topic. That is the point where one hour with a Chemistry specialist saves ten hours of frustrated re-reading. Our free 1-hour trial lesson exists for exactly that diagnosis: a real lesson on your weakest topic, with a specialist, before any payment.

Make the exam the unit of revision

Every revision session should end with the same question: “Could I now earn marks I couldn’t earn this morning?” If the honest answer is “I read about it”, the session failed. If the answer is “I produced it from memory, under time, and checked it against a mark scheme”, you revised the way the A* students do. The full eight-week version of this structure is laid out in our 8-week revision plan.