Year 12 Chemistry students have been studying acid and base reactions as part of the HSC course. For one part of their depth study, they made an indicator from a natural material, in order to generate a pH scale.  They used this scale to predict and determine the pH of other substances based on the colour observed. The natural products that students chose to select included hibiscus leaves, cherries, berries, turmeric, indigo, geranium, beetroot and grape juice. All students were successful in observing a colour difference for acidic and alkaline solutions. They then tested the pH of various household substances to determine the pH based on their indicator scale. Well done Year 12 Chemistry!