Aims
Make a liquid that changes colour.
ExpeRiment to see how the different substances change the colour of cabbage juice.
Learn about the science of indicator solutions and chemical reactions.
About this activity
Andy and his nephews Tom and Tom use chopped up cabbage to make a homemade indicator solution. They then experiment with different household liquids to see what colour changes occur. Their experiments with vinegar, bicarbonate of soda, eggs and anything else they can get their hands on show which liquids are acidic and which are alkaline.
Indicator solutions are important in chemistry, as they reveal useful information about the chemical compositions of other substances. In this experiment, acidic liquids turned the liquid red/pink, while alkaline liquids turned the liquid blue.
It’s fun to just look at the colour changes you can get with cabbage juice but this activity is a great way to introduce children to the idea that we can use chemical reactions to learn about the properties of substances.