neutralisation

Everyday

1. (science) A chemical reaction in which an acid and an alkali (or base) react and cancel each other out, making a salt and water. tree →
2. The act of making something have no effect, or stopping a danger. tree →

In the lessons

In science, neutralisation is used to treat indigestion (an antacid neutralises stomach acid), bee and wasp stings, acid soil (farmers add lime), and in toothpaste. Indicator paper turns green at neutral (pH 7). The general formula: acid + alkali → salt + water. Phrases: «neutralisation reaction», «acid and alkali», «pH 7».

Examples

• Neutralisation happens when an acid reacts with an alkali. tree →
• Indigestion tablets work by neutralisation of stomach acid. tree →
• Acid + alkali → salt + water is a neutralisation reaction. tree →
• After neutralisation, the universal indicator turned green. tree →
• Farmers spread lime on acid soil for neutralisation. tree →
• The bomb squad worked on the neutralisation of the old bomb. tree →

Note

UK spelling «neutralisation»; US spelling «neutralization». Verb: neutralise/neutralize; adjective: neutral. Neutral means pH 7 — not acid and not alkali. Myth: «vinegar for wasp stings and baking soda for bee stings» is a popular tip, but the evidence is weak; safety: a bad sting reaction needs an adult and a doctor.