What is the indicator used in Argentometric titrations?

Why in the redox titration of $KMnO_4$ vs oxalic acid,do we heat the oxalic acid solution before starting the titration?

Two acids $A$ and $B$ are titrated separately. $25 \ mL$ of $0.5 \ M \ Na_2CO_3$ solution requires $10 \ mL$ of $A$ and $40 \ mL$ of $B$ for complete neutralization. The volumes (in $L$) of $A$ and $B$ required to produce $1 \ L$ of $1 \ N$ acid solution respectively are:

During the estimation of oxalic acid $V/S$ $KMnO_4$,the self-indicator is:

An organic dye,eosin,used to detect the endpoint of precipitation titration by adsorption is called:

$300 \ mL$ of deci-molar solution of $Ba(OH)_{2(aq)}$ was titrated with $100 \ mL$ of $0.2 \ M \ HCl_{(aq)}$ solution. The final solution had to be titrated with $V \ mL$ of semi-molar $H_2SO_{4(aq)}$ solution for end-point. Correct option is $V = ....... \ mL$