Cambridge IGCSE·Co-ordinated Sciences 0654·Chemistry
Acids Bases Salts
Key knowledge — Acids Bases Salts
Formulas & equations
acid + metal → salt + hydrogenacid + metal oxide → salt + wateracid + metal hydroxide → salt + water (neutralisation)acid + metal carbonate → salt + water + carbon dioxide
Key facts & rules
- Acid: produces H⁺ ions in solution. pH < 7.
- Alkali: produces OH⁻ ions in solution. pH > 7. (Bases that dissolve in water.)
- Neutralisation: H⁺ + OH⁻ → H₂O.
- pH scale: 0–14. pH 7 = neutral. Strong acids have lower pH than weak acids at same concentration.
- Strong acid: fully dissociates (HCl, H₂SO₄, HNO₃). Weak acid: partially dissociates (CH₃COOH).
- Making insoluble salts: mix two solutions containing the required ions → filter the precipitate.
- Making soluble salts: add excess solid acid/metal/metal carbonate to acid → filter → evaporate.
- Titration: used to find exact volume of acid/alkali needed for neutralisation.
IGCSE Chemistry — Acids, bases & salts
3631 Cambridge IGCSE 0654 chemistry past paper questions on acids, bases & salts, organised by subtopic. Pick a subtopic to start practising.
About acids, bases & salts on IGCSE 0654
The properties of acids and bases, pH, neutralisation, the preparation of salts, and tests for ions. A high-frequency Chemistry topic.