The pH scale is used to measure acidity and alkalinity. When an acid is neutralised, it forms a salt. Making salts Acids react with metals, bases and carbonates to produce salts. Neutralisation is ...

An acid-base indicator is a substance that changes color as the pH of the solution changes. Indicators work because they are weak acids which when in solution, exist in equilibrium with their ...

The pH scale shows how acidic a substance is. Learn what pH means and how it is measured in this KS3 chemistry guide from BBC Bitesize. Neutralisation reactions Acids and alkalis react together in ...