In $Duma's$ method of estimation of nitrogen,$0.35 \ g$ of an organic compound gave $55 \ mL$ of nitrogen collected at $300 \ K$ temperature and $715 \ mm$ pressure. The percentage of nitrogen in the compound is (aqueous tension at $300 \ K = 15 \ mm$). (in $.45$)

Discuss the Dumas method and its principles for the estimation of $N$ present in an organic compound.

In Dumas method for estimation of nitrogen,$0.3 \ g$ of an organic compound gave $41.9 \ mL$ of nitrogen gas at $\text{STP}$. What is the percentage of nitrogen (in $.5$)?

Fill in the blanks:
$(1)$ ........... solution is added to produce the precipitate of $BaSO_4$ in the estimation of sulphur.
$(2)$ .......... and .... precipitate will be produced by the estimation of phosphorus.
$(3)$ How many elements are estimated in organic compounds?
$(4)$ ......... gas is produced in the Dumas method,but ....... gas is produced in the Kjeldahl's method.

In $DNA$ and $RNA,$ nitrogen atoms are present in the ring system. Can the Kjeldahl method be used for the estimation of nitrogen present in these?

Dumas method involves the determination of nitrogen content in the organic compound in the form of