Which compounds are taken in the Kjeldahl's flask for the estimation of nitrogen?

In Dumas method for estimation of nitrogen,$0.50 \ g$ of an organic compound gave $70 \ mL$ of nitrogen collected at $300 \ K$ and $715 \ mm$ pressure. The percentage of nitrogen in the organic compound is . . . . . . $ \% $ (Aqueous tension at $300 \ K$ is $15 \ mm$).

$29.5 \, mg$ 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?

The Kjeldahl method of nitrogen estimation fails for which of the following reaction products $?$
$(a)$ Nitrobenzene $\xrightarrow{Sn/HCl}$ Aniline
$(b)$ Benzonitrile $\xrightarrow{LiAlH_4}$ Benzylamine
$(c)$ Benzyl cyanide $\xrightarrow{(i) SnCl_2 + HCl, (ii) H_2O}$ Phenylacetaldehyde
$(d)$ Aniline $\xrightarrow{NaNO_2/HCl}$ Benzenediazonium chloride

$0.400 \ g$ of an organic compound $(X)$ gave $0.376 \ g$ of $AgBr$ in Carius method for estimation of bromine. The $\%$ of bromine in the compound $(X)$ is $.........$. (Given: Molar mass $AgBr = 188 \ g \ mol^{-1}$,$Br = 80 \ g \ mol^{-1}$)

In Carius method of estimation of halogen,$0.45 \ g$ of an organic compound gave $0.36 \ g$ of $AgBr$. Find out the percentage of bromine in the compound. (Molar masses : $AgBr = 188 \ g \ mol^{-1}$,$Br = 80 \ g \ mol^{-1}$) (in $\%$)