Making your own pH indicator.
Many pigments from flowers and vegetables make good pH indicators but we found one which was fantastic.
It's made from flowers of a plant very common around our school - Butterfly Pea.
Just using the petals, grind them up in a pestle and mortar with
plenty of distilled water. Just 3 flowers will make about 2ml of indicator.
Filter the brilliant blue liquid or use a dropper.
That's it!
It's not a very accurate indicator, but it's great fun to use in Year 7 and Year 8 classes.
Take some samples of acids and alkali to test. Pure water, water with a few drops of lemon juice, vinegar, strong acid in the Science Lab such as dilute HCl, dilute ammonia, dilute sodium hydroxide and a few drops of bleach in water.
Here are our results!
Pink - HCl, Red - vinegar, Purple - lemon juice, Blue -water, Green - ammonia, Yellow - NaOH and the last one was bleach, which we think just bleached the colour out!!
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