The $pH$ range of methyl red indicator is .......?

For an acid-base indicator,the dissociation constant $K_a = 1.0 \times 10^{-5}$. The indicator is red in acidic form and blue in basic form. What is the $pH$ range required for the color change from $80\%$ red to $80\%$ blue?

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

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

$50 \ mL$ of $0.1 \ M$ of a weak acid $HA$ is titrated with $0.1 \ M$ of $NaOH$. The ionization constant of $HA$ $(K_a)$ is $1.8 \times 10^{-5}$. Using the given information and from the options shown below,the best indicator for the titration of $HA$ with $NaOH$ is $....$

The indicator used in titrating a weak acid (e.g.,oxalic acid) with a strong base (e.g.,caustic soda) solution is