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

$100 \ mL$ of aqueous solution of $0.05 \ M$ $Cu^{2+}$ is added to $1 \ L$ of $0.1 \ M$ $KI$ solution. The resultant solution was titrated with $0.01 \ M$ $Na_2S_2O_3$ solution using starch indicator till blue color disappeared. What is the volume (in $mL$) of $Na_2S_2O_3$ used?

The number of equivalents of $Na_2S_2O_3$ required for the volumetric estimation of one equivalent of $Cu^{2+}$ is

Given below are two statements
Statement $I$: Aqueous solution of $K_2Cr_2O_7$ is preferred as a primary standard in volumetric analysis over $Na_2Cr_2O_7$ aqueous solution.
Statement $II$: $K_2Cr_2O_7$ has a higher solubility in water than $Na_2Cr_2O_7$.
In the light of the above statements,choose the correct answer from the options given below:

$A$ $0.166 \ g$ 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 $..... \ \%$.

Estimation of $CO$ is done by using: