Memory Aids
This memory aid covers Memory Aids 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 11 of 17 in this topic. Use it for quick recall, then test yourself straight afterwards so the memory aid becomes usable in an answer.
Topic position
Section 11 of 17
Practice
27 questions
Recall
20 flashcards
🧠 Memory Aids
The formula triangle: Draw a triangle with m (mass) at the top, n (moles) bottom-left, and Mr bottom-right. Cover what you want: cover n → m over Mr → n = m ÷ Mr. Think: "Mr Mole finds the MASS."
For percentage yield: "ACTUAL over THEORETICAL, times a hundred" — A/T × 100. Remember: actual yield is always lower than theoretical in real experiments.
For atom economy: "DESIRED over ALL, times a hundred" — the product you WANT divided by ALL products formed. High atom economy = green chemistry.
Avogadro's number: 6.02 × 10²³ — roughly 600 billion trillion. Think of it as "a million million million million" — impossibly big, which is why atoms are weighed in grams, not counted individually.
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
Instant marking, adaptive difficulty, and 20 spaced repetition flashcards. Free until your GCSEs.
Try PrepWise Free