#75
4.3.1.3 Mass changes when a reactant or product is a gas
Paper 1 · Higher combined
Spec reference: 4.3.1.3 (under 4.3.1).
What you need to know
- (Key facts / definitions / equations for this spec point)
Support videos
- FreeScienceLessons (topic playlist): (use links below)
- FreeScienceLessons (Quantitative chemistry playlist): https://www.youtube.com/playlist?list=PL9IouNCPbCxUhxxFUbR4SNfwmaRB8mYX3
Self-assessment (checklist)
- I can draw tangents to the curves on these graphs and
Key steps (method)
- Identify what the question is testing and use precise chemistry vocabulary.
- If it’s a calculation: write the equation/formula first, then substitute carefully.
Common mistakes
- Missing units/state symbols when asked.
- Giving a statement without linking cause → effect.
Exam-style questions (quick)
- Define the key term(s) for this point in the spec.
- Explain a typical property/result using particle/bonding ideas.
- Do a short calculation or interpretation step relevant to this point.
Practice questions
- PMT: Quantitative chemistry (questions + notes): https://www.physicsandmathstutor.com/chemistry-revision/gcse-aqa/quantitative-chemistry/