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

(N/A) Estimation of nitrogen by the Dumas method:
The nitrogen-containing organic compound,when heated with copper oxide $(CuO)$ in an atmosphere of carbon dioxide $(CO_2)$,yields free nitrogen $(N_2)$ in addition to carbon dioxide and water.
Reaction:
$C_xH_yN_z + (2x + y/2)CuO \xrightarrow{\Delta} xCO_2 + (y/2)H_2O + (z/2)N_2 + (2x + y/2)Cu$
Traces of nitrogen oxides formed,if any,are reduced to nitrogen by passing the gaseous mixture over a heated copper gauze.
The mixture of gases so produced is collected over an aqueous solution of potassium hydroxide $(KOH)$,which absorbs carbon dioxide. Nitrogen is collected in the upper part of the graduated tube (nitrometer).
Calculation of percentage composition of nitrogen:
Mass of organic compound taken $= m \ g$
Volume of nitrogen collected $= V_1 \ mL$
Laboratory temperature $= T_1 \ K$
Pressure of $N_2$ gas at $T_1 = p_1 = (\text{Atmospheric pressure} - \text{Aqueous tension})$
Volume of $N_2$ at $STP = V \ mL$
Using the ideal gas equation: $\frac{p_1 V_1}{T_1} = \frac{p_0 V_0}{T_0}$
Percentage of $N = \frac{28}{22400} \times \frac{V_0 \times 100}{m}$