Free Biology, Chemistry and Physics workbooks: notes, quick checks and exam-style practice. Get them free

Edexcel IGCSE Chemistry · Spec 2.28-2.32

Acids, Alkalis, Indicators & the pH Scale

Acids and alkalis, indicators, and the pH scale.

Chemistry revision video

Acids, Alkalis, Indicators & the pH Scale

Spec 2.28-2.32

What you need to know

  • Use the pH scale to classify solutions
  • Describe indicators and their colours
  • Explain neutralisation

Active recall

Quick check

Answer each question before opening the answer.

What pH values are acidic, neutral and alkaline?

Below 7 is acidic, 7 is neutral, and above 7 is alkaline.

Which ion do acids and alkalis produce in water?

Acids produce H+ ions; alkalis produce OH− ions.

Chemistry video companion

Keep your notes and exam practice together

The free Chemistry workbook follows every video in specification order.