Question 1

How do I get full marks on a 6-mark question in Cambridge International IGCSE Chemistry?

Accepted Answer

Six-mark questions reward both solid knowledge (AO1) and the ability to reason through a problem clearly (AO2), so examiners are looking for scientific explanation, not just a list of facts. Start by identifying the command word, since 'explain' calls for the reasons behind a process, 'describe' calls for observations, and 'evaluate' asks you to weigh up evidence. Some extended questions use levels-of-response marking, where examiners assess how well your ideas connect and flow rather than ticking off individual points, so writing in clear, linked sentences tends to score higher than a list of bullet points. Our exam practice questions show you exactly what a full-mark response looks like in context, and our notes walk through the Chemistry content so you have the precise scientific terminology ready to use when the question calls for it.

Question 2

What do the levels in the Cambridge International IGCSE Chemistry mark scheme mean?

Accepted Answer

In levels-of-response marking, an examiner reads your whole answer and places it into a level based on the quality of your scientific reasoning, rather than awarding one mark per fact you mention. A higher level reflects answers that connect ideas logically, use precise scientific vocabulary, and build a complete explanation from start to finish rather than listing isolated points. Not every question uses this approach, so recognising which style of marking applies to each question type is worth practising. Our exam practice walks you through both marking styles, with mark scheme commentary to show what Cambridge International examiners expect at each level.

Question 3

What's the difference between Cognito's exam practice and past papers?

Accepted Answer

Our exam practice lets you work through questions topic by topic, so you can focus on C7 Acids, bases and salts or C11 Organic chemistry in isolation, without having to sift through biology and physics questions at the same time. That's a genuine advantage with 0654, because Cambridge's Extended papers (Paper 2 and Paper 4) mix all three sciences together, which makes it hard to identify your chemistry weak spots from a full past paper alone.

Past papers are still worth using, especially when you want to experience the real mixed-science format and build a sense of pacing across the whole exam. We'd suggest using our exam practice to build confidence on individual Chemistry topics first, then moving to past papers to put everything together in the actual exam conditions.

Question 4

How long should I spend on each question in the exam?

Accepted Answer

A useful rule of thumb for Paper 4 (the 2-hour Theory paper) is to aim for roughly 1 minute per mark, since the paper carries 120 marks across 120 minutes, which gives you a clear pace to work to. For Paper 2 (the 45-minute MCQ paper), you have just over 1 minute per question across its 40 multiple-choice questions, so we'd suggest moving on promptly if a question is stumping you rather than letting it eat into time for later questions. If you're sitting Paper 5 (Practical Test, 2 hours, 60 marks), that works out to around 2 minutes per mark, while Paper 6 (Alternative to Practical, 1 hour 30 minutes, 60 marks) gives you around 1.5 minutes per mark. Working through our exam practice on Cognito is a great way to build your sense of this pace through active recall before exam day, so the timing feels natural rather than stressful when it counts.