Briefly explain how you would prepare a simple acid base indicator?

To prepare a simple acid-base indicator, you can use red cabbage. First, chop up the red cabbage into small pieces and place them in a heatproof container. Add boiling water to cover the cabbage and let it steep for about 30 minutes. Strain the liquid to remove the cabbage pieces, and you will be left with a purple liquid that can be used as an indicator. This liquid will turn red in the presence of an acid and green or yellow in the presence of a base.