With $63 \ g$ of oxalic acid,how many litres of $\frac{N}{10}$ solution can be prepared?

$A$ $0.166 \ g$ sample of an organic compound was digested with conc. $H_2SO_4$ and then distilled with $NaOH$. The ammonia gas evolved was passed through $50.0 \ mL$ of $0.5 \ N \ H_2SO_4$. The excess acid required $30.0 \ mL$ of $0.25 \ N \ NaOH$ for complete neutralization. The mass percentage of nitrogen in the organic compound is $..... \ \%$.

Which of the following statements is not true about Mohr's salt?

$A$ $2.0 \, g$ sample containing $MnO_2$ is treated with $HCl$ liberating $Cl_2$. The $Cl_2$ gas is passed into a solution of $KI$ and $60.0 \, mL$ of $0.1 \, M \, Na_2S_2O_3$ is required to titrate the liberated iodine. The percentage of $MnO_2$ in the sample is $.....$ (Nearest integer).
[Atomic masses (in $u$): $Mn = 55, Cl = 35.5, O = 16, I = 127, Na = 23, K = 39, S = 32$]

Estimation of $CO$ is done by using:

The required amount of crystalline oxalic acid (equivalent weight = $63$) to prepare $250 \, mL$ of $N/10$ oxalic acid solution is: (in $, g$)