Lesson 4 of 7

Neutralisation

Goal: Describe what happens when an acid and an alkali react.

Puzzles for this lesson

Word search0 of 7 foundCrossword0 of 37 letters
A flask of green liquid under a burette

An acid and an alkali cancel each other out. This is called neutralisation.

acid + alkali → salt + water

  • The pH moves towards 7 as you add alkali to an acid.
  • At pH 7 the solution is neutral. Universal indicator turns green.
  • Add too much alkali and the pH carries on past 7.

Your turn

This lesson’s activity starts here in a moment.

Check yourself

Knowledge organiser

This lesson on one page. Tap it to make it bigger.

Key words in this lesson

Acid Has a pH below 7

Alkali Has a pH above 7

Neutral pH 7, neither acid nor alkali

Indicator Changes colour in acids and alkalis

Universal indicator Shows a range of colours for pH

Neutralisation An acid and an alkali cancelling out

Salt Made when an acid is neutralised

For teachers: AQA 3.6.2 · Pearson Edexcel 24.4, 24.5 · Cambridge 7Cc.04