In the $Kjeldahl$ method,when an organic compound containing nitrogen is heated with concentrated $H_2SO_4$,nitrogen is converted into which of the following?

Kjeldahl's method was used for the estimation of nitrogen in an organic compound. The ammonia evolved from $0.55 \ g$ of the compound neutralized $12.5 \ mL$ of $1 \ M \ H_2SO_4$ solution. The percentage of nitrogen in the compound is $.....$ (Nearest integer).

$0.53 \ g$ of an organic compound $(x)$ when heated with excess of nitric acid (concentrated) and then with silver nitrate gave $0.75 \ g$ of silver bromide precipitate. $1.0 \ g$ of $(x)$ gave $1.32 \ g$ of $CO_2$ gas on combustion. The percentage of hydrogen in the compound $(x)$ is . . . . . . $\%$. [Nearest Integer]
[Given : Molar mass in $g \ mol^{-1} H : 1, C : 12, Br : 80, Ag : 108, O : 16$; Compound $(x) : C_xH_yBr_z$] (in $\%$)

In the Dumas method for the estimation of nitrogen,$0.388 \ g$ of an organic compound yielded $1.31 \ mL$ of $N_2$ gas collected at $293 \ K$ temperature and $746 \ mm$ pressure. Calculate the percentage of nitrogen in the compound. (Aqueous tension at $293 \ K = 6 \ mm$). (in $\%$)

$0.3780 \, g$ of an organic chloro compound gave $0.5740 \, g$ of silver chloride in Carius estimation. Calculate the percentage of chlorine present in the compound. (in $\%$)

$29.5 \, mg$ of an organic compound containing nitrogen was digested according to Kjeldahl's method and the evolved ammonia was absorbed in $20 \, mL$ of $0.1 \, M \, HCl$ solution. The excess acid required $15 \, mL$ of $0.1 \, M \, NaOH$ solution for complete neutralization. What is the percentage of nitrogen in the compound?