This is a hands-on experiment that explains the measurement of pH using red cabbage indicator paper. Are household solutions acidic or alkaline/basic?

These resources were created for the Cambridge science festival 2013.

If you teach primary science, see the headings below to find out how to use this resource:

Skill development

Children will develop their working scientifically skills by:

  • Drawing conclusions and raising further questions to be investigated, based on their data and observations.
  • Asking their own questions about scientific phenomena.
  • Selecting and planning the most appropriate ways to answer questions, including:
    • Grouping and classifying things.

Learning outcomes

Children will:

  • Group substances according to whether they are acidic, neutral or alkaline.
  • Compare and group together everyday materials on the basis of their properties.

Concepts supported

Children will learn:

  • That substances can be acidic, neutral or alkaline, and that tests can be performed to determine which of the three a substance is.

Suggested activity use

You can use this activity as a whole-class investigation, allowing children to group substances into acids and alkalis. It will provide opportunity for discussion and questioning.

Alternatively, you could use this resource as part of a science week or at a science club.

Practical considerations

The red cabbage juice indicator can be prepared the prior to the lesson, which will save time.

A range of different substances to test will be required.