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

For standardizing $NaOH$ solution,which of the following is used as a primary standard?

Temporary hardness in tap water is measured in terms of parts of $CaCO_3$ per $10^6$ parts of water. If $500 \ mL$ of hard water containing $Ca(HCO_3)_2$ was titrated against $\frac{1}{20} \ M \ H_2SO_4$ solution in the presence of a methyl orange indicator,and it required $40 \ mL$ of titrant,then the temporary hardness in the tap water is .............. $ppm$.

The strength of an aqueous solution of $I_2$ can be determined by titrating the solution with a standard solution of:

In the titration of a strong acid and a weak base,the indicator used is:

$3.92 \, g$ of ferrous ammonium sulfate crystals are dissolved in $100 \, mL$ of water. During titration,$20 \, mL$ of this solution is required for complete oxidation by $18 \, mL$ of $KMnO_4$ solution. Calculate the weight of $KMnO_4$ in $1 \, L$ of the solution in grams.