The Balancing Act
📖 The Balancing Act
Neutralisation is like balancing a see-saw! On one side you have acid (H⁺ ions), on the other side alkali (OH⁻ ions). When you add exactly the right amount of one to the other, they combine to form water (H₂O) and the see-saw balances perfectly at pH 7. Too much acid? Tip towards acidic. Too much alkali? Tip towards alkaline. The goal is perfect balance!
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.
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🧠 Memory Aids
Acid + Base = Salt + Water: Remember "ABSW" — Acid plus Base gives Salt and Water. Easy to recall during an exam.
The four reaction types:
- Acid + Metal → Salt + H₂ (squeaky pop test)
- Acid + Metal Oxide → Salt + Water
- Acid + Metal Hydroxide → Salt + Water
- Acid + Metal Carbonate → Salt + Water + CO₂ (limewater test)
Salt naming rule: "Base gives the first name, Acid gives the surname." NaOH (sodium) + HCl (chloride) → sodium chloride. Ca(OH)₂ (calcium) + H₂SO₄ (sulfate) → calcium sulfate.
The ionic equation: H⁺ + OH⁻ → H₂O — just three symbols, always the same. Write it in the margin of your exam paper.
Now try it yourself
Quiz · Question 1 of 20
Which word equation correctly represents a neutralisation reaction?
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This topic in real past papers
Every real exam question we've found on neutralisation reactions, with a full worked answer.