What happens to the halogen when $AgNO_3$ is added to the Lassaigne solution acidified with $HNO_3$?

The volume of nitrogen is measured by which apparatus in the Dumas method?

Match the List-$I$ with List-$II$:

List-$I$ (Reagent)	List-$II$ (Functional Group detected)
$A$. Sodium bicarbonate solution	$I$. Double bond/unsaturation
$B$. Neutral ferric chloride	$II$. Carboxylic acid
$C$. Ceric ammonium nitrate	$III$. Phenolic $-OH$
$D$. Alkaline $KMnO_4$	$IV$. Alcoholic $-OH$

Choose the correct answer from the options given below:

Sodium extract is heated with concentrated $HNO_3$ before testing for halogens because

What is the fundamental principle of the Lassaigne test?

Statement $I$: Nitrogen in pyridine cannot be estimated by Kjeldahl’s method. Statement $II$: Nitrogen in pyridine changes to ammonium sulphate when heated with conc. $H_2SO_4$ in Kjeldahl’s method. Read the above given statements and choose the correct answer from the given options.