The indicator used during the estimation of $COD$ of a water sample is

In the volumetric analysis of $HCl$,if we use phenolphthalein as an indicator,which base is unsuitable for titration?

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

$110 \, mL$ of $0.1 \, N \, HCl$ is titrated with $30 \, mL$ of $0.2 \, N \, NaOH$. The remaining titration is completed by adding $0.25 \, N \, KOH$ solution. What volume of $KOH$ in $mL$ is required?

Which of the following reactions occurs during iodometric titration in the laboratory?

$20 \, mL$ of calcium hydroxide was consumed when it was reacted with $10 \, mL$ of an unknown solution of $H_2SO_4$. Also,$20 \, mL$ of a standard solution of $0.5 \, M$ $HCl$ containing $2$ drops of phenolphthalein was titrated with calcium hydroxide. The mixture showed a pink color when the burette displayed the value of $35.5 \, mL$,whereas the burette showed $25.5 \, mL$ initially. The concentration of $H_2SO_4$ is $..........M$ (Nearest integer).