(This experiment is taken from the RSC exceriment that appeared as part of the Global Water Experiment in 2011)
Two different indicators, bromothymol blue and m-cresol purple are used, which have overlapping ranges. This allows the pH of samples of water to be tested between pH 6.0 and pH 8.8. As such the method can be used for investigating the changing pH of fresh and sea waters as part of an Environmental investigation.
pH of the Planet
pH of the Planet – Risk Assessment