The indicator used in the titration of $Na_2CO_3$ with $HCl$ is..................

The suitable indicator for the titration of a strong acid and a weak base is:

If a very small amount of $HPh$ (phenolphthalein) is added to a $0.1 \ M$ aqueous solution of $CH_3COONa$,the fraction of the indicator that exists in the colourless form is:
$[K_b(CH_3COO^{-}) = 10^{-9}, pK_a(HPh) = 9.6, \log 2 = 0.3]$

If we use phenolphthalein as an indicator in a titration of $Na_2CO_3$ with $HCl$,the usual result is:

Starch can be used as an indicator for the detection of traces of

$A$ 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.