Which indicator is most suitable for the titration of $0.1 \, N \, Na_2CO_3$ solution with $0.1 \, N \, HCl$?

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?

Which indicator can be used in the titration of a strong acid and a strong base?

Methyl orange gives $.......$ color in an acidic medium.

Methyl orange gives red colour in

$20 \ mL$ of $0.5 \ N \ HCl$ and $35 \ mL$ of $0.1 \ N \ NaOH$ are mixed. The resulting solution will