In: Chemistry
Can you use phenolphthalein to titrate a colored solution? Explain please! I can't figure this out.
Phenolphthalein is a colourless chemical compound and used as an indicator in acid-base titration as it it turns colorless in acidic solutions and pink in basic solutions.
Phenolphthalein is a weak acid and doesn't give H+ ion in acidic medium and exist as Phenolphthalein molecule in acidic medium. Hence Phenolphthalein is colourless in acidic medium.
However in basic medium, it acts as an acid and loses H+ ion to react with the base. Hence Phenolphthalein ion, which is pink in colour is formed, making the solution pink coloured.
Phenolphthalein can also be used to titrated a coloured solution, because the colour is itself imparted by Phenolphthalein, and we can observe the colour change in coloured solution also with a little bit more observation.
Also there would not be any problem in determining the acidic medium, as no colour change is observed in acidic medium.
Phenolphthalein can also be used to titrate coloured solution because