What is the sample's alkalinity if the phenolphthalein indicator does not turn the sample pink?
Phenolphthalein alkalinity endpoint from pink to colorless
Phenolphthalein alkalinity uses a phenolphthalein indicator that changes from pink to a colorless endpoint. If the sample does not turn pink after adding the indicator, the sample does not have phenolphthalein alkalinity. The sample will also not have any phenolphthalein alkalinity if less than pH 8.3.