1. Tardigrade
  2. Question
  3. Chemistry
  4. Given below are two statements: one is labelled as Assertion A and the other is labelled as Reason R. Assertion A :Phenolphthalein is a pH dependent indicator, remains colourless in acidic solution and gives pink colour in basic medium Reason R: Phenolphthalein is a weak acid. It doesn't dissociate in basic medium. In the light of the above statements, choose the most appropriate answer from the options given below :

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Q. Given below are two statements : one is labelled as Assertion A and the other is labelled as Reason R.
Assertion $A$ :Phenolphthalein is a $pH$ dependent indicator, remains colourless in acidic solution and gives pink colour in basic medium
Reason $R$ : Phenolphthalein is a weak acid. It doesn't dissociate in basic medium.
In the light of the above statements, choose the most appropriate answer from the options given below :

JEE MainJEE Main 2022Redox Reactions

Solution:

Phenolphthalein dissociate in basic medium $\underset{\text{(Colourless)}}{HPh ( aq )} \rightleftharpoons H ^{+}+\underset{\text{(Pink)}}{ Ph ^{-}}$