For testing halogens in an organic compound with $AgNO_{3}$ solution,sodium extract (Lassaigne's test) is acidified with dilute $HNO_{3}$. What will happen if a student acidifies the extract with dilute $H_{2}SO_{4}$ in place of dilute $HNO_{3}$?

The formulae of ammonium phosphomolybdate $(X)$ and the compound $(Y)$ responsible for Prussian blue colour are:

The Lassaigne's extract is boiled with dilute $HNO_3$ before testing for halogens because,

In Lassaigne's test for the detection of halogens,the sodium fusion extract is first boiled with concentrated nitric acid. This is

Three students,Manish,Ramesh,and Rajni were determining the extra elements present in an organic compound given by their teacher. They prepared the Lassaigne's extract $(L.E.)$ independently by the fusion of the compound with sodium metal. Then they added solid $FeSO_4$ and dilute sulphuric acid to a part of the Lassaigne's extract. Manish and Rajni obtained prussian blue colour,but Ramesh got red colour.
Ramesh repeated the test with the same Lassaigne's extract,but again got red colour only. They were surprised and went to their teacher and told him about their observation. Teacher asked them to think over the reason for this. Can you help them by giving the reason for this observation? Also,write the chemical equations to explain the formation of compounds of different colours.

Match List-$I$ with List-$II$.

List-$I$ Element detected	List-$II$ Reagent used/Product formed
$A$. Nitrogen	$I$. $Na_2[Fe(CN)_5NO]$
$B$. Sulphur	$II$. $AgNO_3$
$C$. Phosphorus	$III$. $Fe_4[Fe(CN)_6]_3$
$D$. Halogen	$IV$. $(NH_4)_2MoO_4$

Choose the correct answer from the options given below: