In an acid-base titration,$0.1 \ M \ HCl$ solution was added to the $NaOH$ solution of unknown strength. Which of the following correctly shows the change of $pH$ of the titration mixture in this experiment?

Which of the following statements is correct?

Can titrations with $KMnO_4$ be performed in the presence of $HCl$? Why?

In the titration of $KMnO_{4}$ with $C_{2}O_{4}^{2-}$,which temperature range is not proper? Why?

Consider the titration of $NaOH$ solution versus $1.25\, M$ oxalic acid solution. At the end point,the following burette readings were obtained:
$(i)$ $4.5\, mL$ $\quad (ii)$ $4.5\, mL$ $\quad (iii)$ $4.4\, mL$
$(iv)$ $4.4\, mL$ $\quad (v)$ $4.4\, mL$
If the volume of oxalic acid taken was $10.0\, mL$,then the molarity of the $NaOH$ solution is .... $M$ (Rounded-off to the nearest integer).

An aqueous solution of oxalic acid dihydrate contains $6.3 \ g$ in $250 \ mL$. The volume of $0.1 \ N \ NaOH$ required to completely neutralize $10 \ mL$ of this solution is $.............. \ mL$.