Try this investigation to get learners thinking about when an irreversible reaction produces a gas

This resource is also available in Welsh and Irish

This experiment focuses on reacting vinegar and bicarbonate of soda to produce carbon dioxide gas. First watch the video showing the ‘freaky hand’ demonstration, then find out how to run this as an investigation to explore irreversible reactions.

Learning objectives

  • To describe the difference between a reversible and an irreversible change.
  • To explain that mixing some materials can result in the formation of new ones (in this case, one of these is carbon dioxide) and that this kind of change is not reversible.
  • Understand that gases expand to fill their container.

Enquiry skills:

  • To be able to use results to make predictions to set up further comparative and fair tests.

Watch the video

The video demonstration below shows how to carry out the ‘feaky hand’ experiment.

Source: Royal Society of Chemistry

Make a freaky inflatable hand to demonstrate irreversible reactions to primary students.

Download the supporting materials

Set up and run the investigation with your class using the teacher notes and classroom slides, featuring a full equipment list, method, key words and definitions, questions for learners, FAQs and more.

Teacher notes

PDF | Editable Word document

Classroom slides

PDF | Editable PowerPoint document


What do learners need to know first?

Learners must have an understanding of the properties of solids, liquids and gases and the behaviour of their particles in each state.

Learners must also have investigated reversible changes and be able to give examples of reversible changes.

Equipment list

  • Disposable, stretch latex gloves (careful of latex allergies)
  • Bicarbonate of soda
  • Vinegar
  • Teaspoon
  • Small jam jar, cup or beaker (the neck should be wide enough to give a tight seal with the gloves)

Additional resources