Given below are two statements: one is labelled as Assertion A an… - Vidyadip

MCQ

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.

A
Both $A$ and $R$ are true and $R$ is the correct explanation of $A$
B
Both $A$ and $R$ are true but $R$ is NOT the correct explanation of $A$.
C
$A$ is false but $R$ is true
✓
$A$ is true but $R$ is false

✓

Answer

Correct option: D.

$A$ is true but $R$ is false

d
Phenolphthalein dissociate in basic medium

$HPh ( aq ) \rightleftharpoons H ^{+}+ Ph ^{-}$

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