Unit 3 — Stoichiometry
Formulae Chemistry Topical Past Papers — O Level
Real Cambridge exam questions on Formulae, compiled by topic rather than by year — not a yearly past-paper archive, just this topic on its own. Newer files include their own answers.
CambridgeO Level
Formulae Topical Past Papers
Topical Past Papers coming soon
Resources for this topic are being prepared.
In the meantime, here are a few places that might help instead: