What is $CHN$ analysis in organic estimation?

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 $.5$)?

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

In Carius method of estimation of halogen,$0.25 \ g$ of an organic compound gave $0.15 \ g$ of silver bromide $(AgBr)$. The percentage of Bromine in the organic compound is $.......... \times 10^{-1} \%$ ($Nearest$ integer). (Given: Molar mass of $Ag$ is $108 \ g \ mol^{-1}$ and $Br$ is $80 \ g \ mol^{-1}$)

For the estimation of nitrogen,$1.4 \ g$ of an organic compound was digested by Kjeldahl method and the evolved ammonia was absorbed in $60 \ mL$ of $\frac{M}{10}$ sulphuric acid. The unreacted acid required $20 \ mL$ of $\frac{M}{10}$ sodium hydroxide for complete neutralization. The percentage of nitrogen in the compound is .....$\%$

Fill in the blanks:
$(1)$ .......... gas is produced in Kjeldahl's method and absorbed in ...........
$(2)$ The excess $H_2SO_4$ is added in Kjeldahl's method and then the remaining $H_2SO_4$ is titrated with a calculated ..........