$2.52 \ g$ of oxalic acid dihydrate was dissolved in $100 \ mL$ of water. $10 \ mL$ of this solution was diluted to $500 \ mL$. The normality of the final solution (in $N$) and the amount of oxalic acid (in $mg/mL$) in the solution are respectively

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

During the preparation of Mohr's salt solution (Ferrous ammonium sulphate),which of the following acid is added to prevent hydrolysis of $Fe^{2+}$ ion?

Identify the incorrect statements regarding primary standard of titrimetric analysis.
$(A)$ It should be purely available in dry form.
$(B)$ It should not undergo chemical change in air.
$(C)$ It should be hygroscopic and should react with another chemical instantaneously and stoichiometrically.
$(D)$ It should be readily soluble in water.
$(E)$ $KMnO_4$ and $NaOH$ can be used as primary standard.
Choose the correct answer from the options given below:

The ammonia evolved from the treatment of $0.30 \, g$ of an organic compound for the estimation of nitrogen was passed in $100 \, mL$ of $0.1 \, M$ sulphuric acid. The excess of acid required $20 \, mL$ of $0.5 \, M$ sodium hydroxide solution for complete neutralization. The organic compound is:

Estimation of $CO$ is done by using: