A couple of the children had a presentation to make at school. After much discussion we decided that we would make a pH indicator, and use that.

We found online a couple of recipes, (which I’ll add) and made some, soaked some paper towels …

The recipe that we followed was to use some purple cabbage, boild it up an collect the purple liquor. Cool it and test it.

So we added some Citric Acid and it went red and then added some Sodium Bicarbonate to it. The solution bubbled, and once we added enough the solution went green.

Hey presto – homemade indicator….