This is the most important equation in acid-base chemistry. When hydrogen ions from an acid meet hydroxide ions from an alkali, they combine to form water — a neutral substance. The acid and alkali cancel each other out.
The general equation:
acid + alkali → salt + water
Example reactions:
HCl + NaOH → NaCl + H₂O
hydrochloric acid + sodium hydroxide → sodium chloride + water
H₂SO₄ + 2KOH → K₂SO₄ + 2H₂O
sulfuric acid + potassium hydroxide → potassium sulfate + water
HNO₃ + NaOH → NaNO₃ + H₂O
nitric acid + sodium hydroxide → sodium nitrate + water
This deep dive covers Deep Dive: The Core Neutralisation Reaction within Neutralisation Reactions for GCSE Chemistry. Revise Neutralisation Reactions in Chemical Changes for GCSE Chemistry with 20 exam-style questions and 20 flashcards. This topic appears regularly enough that it should still be part of a steady revision cycle. It is section 2 of 13 in this topic. Use this deep dive to connect the idea to the wider topic before moving on to questions and flashcards.
Practice questions for Neutralisation Reactions
Which word equation correctly represents a neutralisation reaction?
Explain why the ionic equation for any strong acid-alkali neutralisation is always H⁺(aq) + OH⁻(aq) → H₂O(l).