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Separate Chemistry · Paper 1 · Higher Tier only

Theoretical yield and choosing a route

Key ideas1 of 4

Start with moles

Higher Tier: calculate theoretical yield from the balanced equation. For 2Mg + O₂ → 2MgO, magnesium and magnesium oxide have a 1:1 mole ratio. Use excess oxygen and Aᵣ(Mg) = 24, Aᵣ(O) = 16.

A calculation route from 12 grams of magnesium through 0.50 moles to a theoretical yield of 20 grams of magnesium oxide.

Next: Concentration in mol/dm³ →
Practice, downloads and sources

Daily 5 · Exam practice · Revision sheet ↓

Higher Tier only. Use alongside the shared C1–C5 lessons.

AQA GCSE Chemistry 8462 · 4.3.3–4.3.5. Original teaching notes, questions and diagrams.