$A$ compound '$X$' is a weak acid and it exhibits colour change at $pH$ close to the equivalence point during neutralization of $NaOH$ with $CH_3COOH$. Compound '$X$' exists in ionized form in basic medium. The compound '$X$' is.

The pink color of phenolphthalein in an alkaline medium is due to:

Which indicator is useful for the titration of a weak acid and a strong base?

Phenolphthalein is not a good indicator for titrating :-

Given below are two statements :-
Statement $I$ :- Methyl orange is a weak acid.
Statement $II$ :- The benzenoid form of methyl orange is more intense/deeply coloured than the quinonoid form.
In the light of the above statements,choose the most appropriate answer from the options given below :-

Indicator for the titration of $HCl$ and $Na_2CO_3$ would be