During the quantitative estimation of $C$ and $H$,the $CO_2$ produced is absorbed in which of the following?

In the sulphur estimation,$0.471 \, g$ of an organic compound gave $1.44 \, g$ of barium sulphate. The percentage of sulphur in the compound is $...... \%$. (Nearest integer)
(Atomic Mass of $Ba=137 \, u$)

In Kjeldahl's method for the estimation of nitrogen,the formula used is

During the estimation of nitrogen present in an organic compound by the Kjeldahl method,the ammonia evolved from $0.5 \ g$ of the compound neutralized $10 \ mL$ of $1 \ M$ $H_{2}SO_{4}$. Find the percentage of nitrogen in the compound. (in $\%$)

For which of the following compounds can the Kjeldahl method be used to determine the percentage of nitrogen?

In Kjeldahl's method for the estimation of nitrogen,$3.88 \ mg$ of an organic compound produces ammonia which requires $5.73 \ mL$ of $0.011 \ N$ $HCl$ for neutralization. Calculate the percentage of nitrogen in the compound.