What weight of ferrous ammonium sulphate is needed to prepare $100 \, mL$ of $0.1 \, N$ solution? (mol. wt. $392$)

$30 \ mL$ of acid solution is neutralized by $15 \ mL$ of a $0.2 \ N$ base. The strength of acid solution is $.............. \ N$.

$10 \, mL$ of concentrated $HCl$ were diluted to $1 \, L$. $20 \, mL$ of this diluted solution required $25 \, mL$ of $0.1 \, N$ sodium hydroxide solution for complete neutralization. The normality of the concentrated hydrochloric acid will be:

Which of the following is used as an oxidizing agent in volumetric analysis?

$20 \, mL$ of a solution of a weak monobasic acid neutralizes $22.18 \, mL$ of a solution of $NaOH$,and $20 \, mL$ of $N/10$ $HCl$ neutralizes $21.5 \, mL$ of the same $NaOH$ solution. The normality of the acid is nearly $.......$ $N$.

The volume of $\frac{N}{10}$ $NaOH$ required to neutralize $100 \ mL$ of $\frac{N}{25}$ $HCl$ is......$mL$