Exam Tips for Moles
This exam tips covers Exam Tips for Moles within Moles & Calculations for GCSE Chemistry. Revise Moles & Calculations in Quantitative Chemistry for GCSE Chemistry with 27 exam-style questions and 20 flashcards. This topic shows up very often in GCSE exams, so students should be able to explain it clearly, not just recognise the term. It is section 16 of 17 in this topic. Treat this as a marking guide for what examiners are looking for, not just a fact list.
Topic position
Section 16 of 17
Practice
27 questions
Recall
20 flashcards
💡 Exam Tips for Moles
🎯 Common Question Types:
- Calculate Mr of a given compound (1-2 marks)
- Multi-step moles calculation using a balanced equation (3-4 marks)
- Calculate percentage yield given actual and theoretical yield (2-3 marks)
- Calculate atom economy from a balanced equation (2 marks)
- Explain why mass appears to change during a reaction (2-3 marks)
📝 Key Command Words:
- Calculate: Show all working; include units in final answer
- Explain: State the principle (conservation of mass) and apply it to the scenario
- Suggest: Give a scientific reason why yield might be less than 100%
- Show that: Work towards the given answer, showing every step
⚠️ Common Mistakes to Avoid:
- Forgetting to divide cm³ by 1000 when using concentration formulas (1 dm³ = 1000 cm³)
- Not using the mole ratio from the balanced equation (the coefficients matter!)
- Rounding too early — only round at the very final step
- Confusing atom economy with percentage yield — atom economy is theoretical, yield is experimental
- Forgetting that Mr has no units
Keep building this topic
Read this section alongside the surrounding pages in Moles & Calculations. That gives you the full topic sequence instead of a single isolated revision point.
Practice Questions for Moles & Calculations
One mole of any substance contains how many particles?
Explain why the percentage yield of a reaction is never 100% in practice.
Quick Recall Flashcards
27 questions on Moles & Calculations — practise free
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