"24 is the magic number at RTP" — one mole of any gas = 24 dm³. Think of it as "two dozen" — 24 dm³, just like 24 hours in a day or 24 items in two dozen.
The gas triangle: Draw a triangle with Volume (V) at the top, Moles (n) bottom-left, and 24 bottom-right. Cover V → n × 24. Cover n → V ÷ 24. This is the gas equivalent of the moles triangle.
Unit check mantra: "cm³? Divide by 1000 to get dm³ FIRST." Always convert before using V = n × 24.
Multi-step route: "mass → moles → ratio → moles of gas → volume" — always follow this sequence for complex questions.
This memory aid covers Memory Aids within Gas Volume for GCSE Chemistry. Topic 19: Gas Volume It is section 8 of 11 in this topic. Use it for quick recall, then test yourself straight afterwards so the memory aid becomes usable in an answer.
Practice questions for Gas Volume
What is the molar gas volume at RTP (room temperature and pressure)?
Explain why the molar gas volume of 24 dm³/mol is only valid at RTP.